This content is an introductory lecture for a General Chemistry course, outlining the course structure, communication methods, and the fundamental concepts that will be covered across two semesters, emphasizing chemistry as a foundational science.
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Okay, good morning. My name is
Khan Vinos, and I'm in charge of the course. I
wanted to let
that there are a lot of students starting the course; it usually
ranges between 600, 700, and 800. Therefore,
much of our communication will
be through the web. We have a
page where you'll find everything
you need for the chemistry course.
First of all, the
lecture presentations will
be available on that website. They're in
PDF format, so
you don't have to copy them into the
presentations; otherwise, you can simply
use them to take notes.
On this page I'm linking to, you'll find
the general chemistry course. Once you're
accessing it, you'll
have all the necessary information
regarding how the course works, the
cost of the course, and
all the materials posted on the bulletin board. You'll also
bulletin board. You'll also
receive a bulletin board notification
so we have something to let you know. This is
the most efficient way for
us. You'll be required to be on
that list to receive a notification,
and you'll have all the materials available on the page.
Now, let me tell you... A little bit of what you'll have available,
like your general planet course,
we're going to start this forest with a
definition of chemistry.
I found this: chemistry is the science
that studies and describes matter, its
chemical and physical properties, the
chemical and physical changes it undergoes, and
the energy variations that accompany
these processes. So, we're going to
start by describing
the constitution of matter.
Then we'll move on to see what the
programs will show us. We'll gradually move
from atoms and molecules and then
that we study. So, in the chemistry course, you'll see
the fundamentals of all branches
of chemistry. That's why we
consider our subject to be the foundation of
your knowledge. In other words, we're going to talk about the
fundamentals of chemistry that you need and
that you'll use in all subsequent courses
of inorganic chemistry,
organic chemistry, or general chemistry. In all
chemistry courses, you'll use the
knowledge you acquire here in
So, I wanted to tell you a little bit about what we're going to
see. This is the topic of chemistry with
us, to enjoy two
chemical subjects for students now in this
semester and in the next. Second semester,
general technical course.
So, in this semester, chemistry is for
the student. We're going to talk about the
basic concepts of the structure of
matter, the electronic structure
of atoms, and the
periodic properties of electronic polys, the physical states
of matter, and thermodynamics, which we're going
to see because we need it as a
tool to study bonding:
ionic bonding, covalent bonding, and
finally other chemical forces. This
will allow us to apply
all the knowledge acquired
to elucidate aspects
about solids, liquids, and
gases, and about bonding based on the type
of bond that these
plants or molecules present.
And well,
in the second semester, we're going to advance
a little more; that is, we're going to move from
atoms and molecules
to chemical reactions, and we're going to
study different aspects of
chemical reactions.
The first thing we'll discuss, which we call
mass relationships, is in reactions,
in what you usually call symmetry.
symmetry.
The rate of reaction is
symmetrical, the degree of progress of the
reactions. When we study chemical equilibrium, we'll study
reactions based on precipitation reactions and
precipitation reactions.
And then the next aspect What we're going to
see are energetic aspects of
reactions and finally processes, reducing
both equalization and the study of
electrolysis cells and barredos.
So, the second semester will
focus on chemical reactions and the
study of different aspects
Regarding the current course,
General Chemistry 1, we returned to
in-person classes and went back to the
way we've
traditionally taught courses, with some
additions for this
year to facilitate the transition from so much
virtual learning to in-person learning.
So, we're going to
have two modalities for the
STEM and General Chemistry courses, and a practical one.
Remember that first of all, we have
a theoretical part, which consists
of the class we're having
today, which will be
virtual. We'll always have this
schedule on Tuesdays, the 12th, and
then all the steps
of the recorded class will be available so you
can study. That is, either in person or through
person or through
the recorded class. Regarding the
practical part of the course, which can be done
in two modalities: in person or
virtually, and for example, construction.
More flexible, or since the
in-person format involves 12 groups,
you've been signing up for. You need to
start paying attention to
the messages we send you because those of you who
I know
always ask me about the many people left out, you'll
all have
a place in the practical course. Without a
doubt, don't worry. What you have
to do is follow the procedure
indicated on the website. You have to fill out
your requests for group changes
or group changes for work, and you will be
assigned to groups.
Attendance is mandatory for these twelve groups. It's
a three-hour practical class
because we've returned to in-person classes.
We have an initial 45-minute
consultation period, which is not mandatory.
During those 45 minutes, you can
ask questions about previous classes.
Therefore, next week, when
the practical course begins,
remember that you won't have those 45 minutes
because you'll be picking up the
instructors at the lecture hall. That's the
first class, so there's no
consultation because there are no
previous classes. So, except for the class that
comes next week... The first practical class is practical;
all the others have those 45
minutes of consultation, which is not
mandatory, where you can
ask the teacher anything you
need to know.
We have a 15-minute break, and
then two hours that are mandatory.
If you have mandatory attendance
in the face-to-face course,
and according to the regulations, you have to
have 80% attendance, that
attendance, that
is, if it's going to be a roll call, that's what I mean.
mean.
Regarding the flexible or
distance learning modality, it's not like you have a fixed classroom
because there isn't a class. What
you have is a lot
of materials, the same as in the face-to-face course,
plus others, and in
exchange for not having
mandatory attendance, you have to complete
complete
virtual activities. These are mandatory, and
again, you have to complete them
satisfactorily, meaning
with an
adequate level of correct answers. You
also have to have 80
% of the activities submitted on
time. You will see that you have a schedule
and this year we added weekly consultations, the
times of which we will give you, where you have
open attendance sessions where you can
come online to consult with a teacher. Regarding
your questions, Texas,
what materials will we have available?
We have a lot. On the one hand, we have the
recorded theory, which is available for
both modalities on the course website. You'll
see how the practical course works. We have
weekly handouts that contain two types of exercises:
exercises:
application exercises and self-assessment exercises.
self-assessment exercises.
The application exercises are
those we've chosen as
representative so that you
learn the content of
this week's topic, and they will
always be solved in the face-to-face class. In
addition, the handouts also include
self-assessment exercises where you will
solve exercises testing what you
learned in the
application exercises. You can do this at home and
have the opportunity to ask questions in
the consultation sessions or through the academic forum. You will also
have access to materials
for each topic, prepared by the faculty,
which we will upload
weekly. These materials contain the
theoretical foundations of the topic covered that week.
week.
We also have an
administrative forum, which is strictly for
for
administrative questions, and an academic forum
where a teacher will
answer your questions daily.
Regarding the resolution of
the three exercises on
theoretical concepts, they were covered in the theoretical section.
And another very important thing you have now, which you didn't have before, is that
during the pandemic we created materials.
So, both in the in
-person and flexible learning modalities, you will have access to
to
videos corresponding to the resolution
of the application exercises in the
practical class. These are
application exercises solved by a teacher or by a teacher. This material was
developed during
the pandemic and will now be kept available
as additional resources for you.
Another thing you will have is also a
result of pandemic-related materials.
During the pandemic, we changed the
course format and had
shorter classes where we solved
more advanced and
applied exercises from the following topics.
You will have access to
these exercises in the handout that
contains them, and you will
also have access to the solutions.
This is optional; you can use
the additional material if you want it to
to study.
study.
So, as you can see, we have a set of
materials available for you
both in the in-person and flexible learning modalities. We
also have ways for
you to
contact us.
Questions besides the consultation class,
the schedule, sorry, the prior consultation
that you have in each face-to-face class, yes, well,
the details of each modality will
be on the website. For the
flexible modality, now you have to sign up, you
have to request the
flexible modality in Greece, and then once
you make this request, which
involves signing a
confidentiality agreement because there are
additional materials
that are not for the face-to-face classes, that
are only for the flexible modality,
so you will have to sign that there. You will
also be given a schedule
for submitting the activities through the
given access to the
flexible modality as soon as possible. Now, those who didn't
do that don't have access, but don't worry, you will be
enabled to
enter the flexible modality and
start seeing the materials and start working.
Well, I think I haven't forgotten anything about how it works.
works.
Anyway, the details of how it works
are on the course website, and you
have your
face-to-face teachers to ask questions about it,
and the forum, the flexible forum,
where you can also ask
questions about how the
flexible or distance learning modality works, the virtual modality. Well, so you're going
virtual modality. Well, so you're going
to To continue the class, we're going to trivialize it with
a social class, which is more of a
review of different topics that
you need to know beforehand
in order to work on the feasible lines course that
the professor will be teaching.
So, well, I'll say goodbye to
you, and we'll be available for any
any
questions you may have later through
said tonight was to share.
Well, as Dinora said,
today's class is, in a way, a
review class because we're going to see
topics that are listed there, which
most of you
have probably seen in previous
chemistry courses, for example, in secondary school, and we
also saw them with those who
participated in the leveling course we had
during the
month of March. So, basically,
the content of today's class will be
about what matter is, how it is
classified, and what type of matter
is distinguished and known as a
mixture, a substance, an
element, a compound, and more. At the
end of the class, we're going to see about
[Music] Okay, so
to begin,
since chemistry is The science that
studies matter and its
transformations, so we need to
know what we mean when
we talk about matter. Matter is
practically everything we
know; anything that has
mass and occupies a certain volume—everything
that constitutes the tangible universe
see that in
science we tend to classify things, making
many classifications. Matter is
classified into two main groups. One of
them is substances, or perhaps
you might know them as pure substances. The
other group is mixtures, and within mixtures, there are
two types.
types.
Substances can be differentiated
into elements and compounds, which we'll
see what each of these
terms means. Mixtures come in two
types: homogeneous mixtures and
heterogeneous mixtures.
Sorry, I forgot to mention that if you have
any questions, raise your hand and
one of my classmates or I will
give you the floor.
Before we continue, please enable the microphone and gloves.
So, this is the
general classification of matter. Now
we'll see what each of these terms means. So, to begin, let's
look at what a
substance is. A substance is
a form of matter with a
defined and constant chemical composition, which in
turn gives it
properties that are also defined
and constant.
What does this imply? That different
substances will have different
compositions and different properties. It's
true that some substances will be more
similar to each other and will have
properties that behave
similarly, but strictly speaking, each
substance has properties that
characterize it and, of course, a
composition. It's very important to
remember that this composition is
defined and constant. For example, what
is given by the chemical formula of a
As an example of a substance familiar
to you, we can mention sugar,
since what is written below is
precisely the chemical formula. So, what does
this formula indicate? Well, that in the
sugar molecule there will be a
certain number of
carbon atoms, which in this case are
12, a certain number of
hydrogen atoms, which are 22, and 11 oxygen atoms.
This is the formula for sugar, and there is no
other. And if there is any change in
these numbers, or if any
element is added, the substance will cease to
be sugar. To be a
different substance, and sugar, as you
know, has certain
characteristics. For example, I can
look at it and see that it's an
apparently white solid. Moreover, under a
microscope, it's crystalline.
If I taste it, I know it has a
sweet flavor, and all those things that one can
can
measure or determine in some way, the
properties or characteristics of
And well, it's not the only example we
have here. Another example is a substance
in a liquid state, for example, water.
You all know very well what the
formula for water is, and it's also a
formula that indicates its composition. [Music]
[Music]
Substances can also be in a
gaseous state, or in this case, what
we show in this photo is nitrogen,
which is actually very much a liquid
that, when placed in a container, becomes a
gaseous state.
And finally, we have here a photo of
silver crystals. The silver used to
make jewelry, etc., in
crystalline form is a
completely different substance from the others, and each
one has very different properties in terms of the
method of aggregation. You
can see that they are different.
Let's move on to see, then, what a mixture is, as
opposed to a substance. So,
we said that a substance has a
defined and constant composition. A mixture is a
combination of two or more substances,
and therefore it can be made up
of varying amounts of these
substances. In other words, a mixture is not
necessarily always the same. And
in that mixture, each of the
substances that compose it maintains its
identity and properties.
A typical example of a mixture is
air. For example, here in
Montevideo at sea level, we have an
air composition that is very similar
to what is shown in this
pie chart above, where we know that there is
approximately 78% nitrogen and 21% oxygen.
oxygen.
But this air composition
is the general one here at
sea level; it is not the same, for example, in the
city of La Paz in Bolivia at 3600
meters above sea level, where the amount of
oxygen is lower. That is, the air mixture
is not necessarily always the same.
And the air, for example, near a
factory where gases are being emitted as a
product of production in the surrounding
area, the composition of the air
can also be different.
So, we see that the composition of mixtures
can be variable.
However, if I were to separate the mixture...
In its
constituent substances,
in 11 of its components, they will be
found unaltered if I can
recover them in a certain way. As long as there is
a process, a physical method by which
a mixture can be separated, I will
recover each of its components. They will
form unaltered. If the
air, nitrogen, and oxygen, the other
gases that compose it, were separated, and it is active, well,
for example, I could have the bases
in individual containers and each
of them would maintain its characteristics
as a substance, just as we saw earlier.
These are what I was referring to when I mentioned air,
without telling you what type of mixture it was.
But two types of mixtures can be distinguished;
that is what we saw in the
diagram. In the classification,
the two types of mixtures are
homogeneous mixtures and
heterogeneous mixtures. So what do I mean
when I say homogeneous mixture? Well, I am
talking about a mixture that has a
uniform composition and therefore
uniform properties. That is, the substances that are
mixed, two, three, or more,
are distributed within that mixture
in such a way that
one portion cannot be distinguished from another.
So we have several types. You
know, for example,
We've talked about leveling solutions,
and there are other types of homogeneous mixtures
that might seem less intuitive to imagine,
imagine,
but metal alloys like
Superman steel beams for
construction are also
homogeneous mixtures. These are solid solutions,
in fact. And here I've given you an example so
that you can
better understand the composition and
properties of uniform materials. What does this
mean? I have, for example, a
photo of some coins from Uruguay. What does it
mean? That a property is
something I can measure or determine
in some way.
In one case, through a chemical method, for
example, the composition can be determined
if I cut
these one-peso and
two-peso coins from Uruguay into many tiny pieces. What I'll
find is that, at one time, a few
years ago,
the gold part
of the coins was made
of an alloy that was 92 percent
copper, 6 percent aluminum, and 2 percent
nickel. What does this mean? That any
portion of the coin that I take and
analyze further will have this same composition, and
this composition, in turn, gives
certain characteristics to that coin, just like the
two-peso coin, the
five-peso coin, and so on. On the
other hand, the ten-peso coins
have the same composition in the center
and the outer part is made of stainless steel. So,
if I look at the whole, I distinguish two
separate parts, but the
inner part is always the same. That
is, this composition is constant throughout the entire coin.
coin.
A heterogeneous mixture, well, we can
define it by the fact that they don't
have a uniform composition and properties.
And here in this example, we have
an example of sand and iron,
which would be something Quite visual, or
for example, this jar
contains stones and seeds of
different types. At first glance, you
can distinguish that there are
different phases because there are different
components in this mixture. This is
something that can't be done in a homogeneous mixture.
We also said that
substances would be classified into two groups,
groups,
one of which was the elements.
Elements are basically what we're dealing with. So, throughout
the entire
chemistry degree, starting in the general chemistry course,
we'll always be
referring to them, as well as the
periodic table. Therefore, we need to be
very clear about what they are.
Here's the definition: an
element is a substance that cannot be
broken down into simpler substances
by chemical methods.
We're going to distinguish between
chemical methods and
physical methods, by which
a mixture cannot be separated,
for example. By chemical methods, we
mean, for example, a
chemical reaction. An element cannot be
broken down; that is, it's the simplest type of
substance we
are 83 naturally occurring elements, and to this day
there are 35 artificial elements,
giving a total of Of the 118 elements that are
organized in the
periodic table, as we'll see now,
each element has a symbol that
identifies it. The symbol of an element
can be one or two letters; generally,
sometimes there are three, but the most typical is one
or two letters.
Each symbol is associated with a
We say it's like
having a
new language, an alphabet, a
new language that you will have to
learn throughout the general chemistry course.
And you will continue learning
later what nomenclature is,
in order to communicate at a
universal level. All chemists
communicate using this language. You will have to
learn it in your coursework, but that's
also why we're here.
For example, in today's class, we're
Here are some examples of
element names so you can see that
names can actually refer
to a lot of different things.
We have elements like argon, which
originates from the Greek word "argos,"
meaning inactive or inert. It
is one of the gases. Of
the noble gases, which react very little, they were
named based on some
characteristic of theirs.
Chromium, for example, comes from the word "
chroma," which means color. There are other
elements like curium,
named after two people:
Pierre and Marie Curie. There are several
elements named after
scientists who discovered them or who
had an important role in
the discovery process, and so they are
named in their honor.
We have, well, several that refer to
color, like iron, from the word "
technically speaking, like technetium, which
means artificial. And vanadium, which isn't named after a
a
Norse goddess; look it up in the Gala of
Injured Stars. This fact is something I didn't know.
know.
And so, there are various names. There are
names from the cities where they were
discovered, etc. There are a
number of different things,
and as I was telling you all, they are
organized in the periodic table,
which is this table we have here.
You probably know several types; you
buy them at the newsstand, they are
cardboard, and there are different versions. You
can see them on the internet, some
interactive ones, and books always... They are in
a periodic table on the back cover of
chemistry books. All of them are
valid to use, and you will see
that some have more elements than
others because, in this case, well, here I
added the most recently
discovered elements. Some of you may or may
not have them. I'm always asked in the leveling course
if it's important that the book has all
118 elements or if it's missing one. It doesn't matter
because most of the chemistry
you will study will be dedicated
to all the other elements, which are the
known and most stable ones.
But anyway, these are organized in the
periodic table, which has this shape that
seems strange because each of
the sections of the tables has
a different meaning, which we will discuss
discuss
later. They are different parts of the table
table
in which the elements are organized, and
the elements are ordered in the
periodic table in increasing order of
atomic number, that is, starting with hydrogen,
passing through helium, lithium, and beryllium, and
so on. The atomic number of
these elements increases; the
atomic number is the number of protons.
And one more comment regarding the
names of the elements,
which you need to know can be two
letters or The symbol for elements is three letters. When
elements are first synthesized,
sometimes the laboratory gives them names.
For example, element 117, which is
Inception, has a symbol like this,
but later it can be called
a common name, a
familiar name. In this case, it was called Tennessine,
after the city in Tennessee where the
laboratory where it was discovered was located. It
ends up appearing in the table with
this other name. But these types
of symbols exist, and there's another type of
nomenclature that is used to
So, we're going to see the symbols of the
elements represented
in a diagram like this, and we're going to
see what each part means. For the
letter, in this case, it's the letter that
symbolizes what I was explaining, what has to do
with the name. And then there's
some other information that's written
around it, depending on what
one wants to refer to. So,
for example, the numbers, the zetas, which
are the ones here on the left.
Well, I mentioned the atomic number,
which is the number of protons, and it's what
gives the order in the periodic table. It's the
zeta, which is a number that is usually
written in the lower left corner.
The law of the symbol for the letter is that
the symbol of the element, the letter or letters,
and the one written with a
symbolic base is the mass number,
which is the number of protons plus the
number of neutrons. It goes up here on the
left side, towards the top. So,
for example, if one wants to mention a
certain isotope of an element, what one
does is write the symbol with the
atomic number and above it the
mass number, which is the sum of
the number of neutrons, which is what
distinguishes one isotope from others. For example,
example,
and we have here this X, which is what is
called the charge, which is the number of
atoms per molecule. In the case of
wanting to describe an element, for example,
hydrogen, hydrogen in its natural state
forms molecules of
two atoms of hydrogen. It would be written,
And finally, what we have at the top
right is the charge. The charge is
written when we are
talking about ions. The charge is written
as the charge number first and then
the positive or negative sign, whether it's a
truck with a positive charge or an animal with a
negative charge.
We always write all four numbers.
Sometimes, first, the
double one is omitted, and
sometimes we don't distinguish
isotopes, so we don't write the
mass number, nor the Z number,
necessarily. But well, that
depends on the information we're
given in each
And well, because of the structure of the
periodic table, as I was saying, it has this
shape; it's a bit strange, but not
arbitrary, of course.
And the periodic table basically has
what are called groups or families, which
are each of the columns we see
in the table. The groups in the
families are numbered from 1 to 18,
starting with the first group
on the left, which is the
alkali metals, one
of those with a proper name, and
ending with the noble gases,
which is number 18. It
also has what are known as
periods, which form the rows
of the table—seven periods in total.
So, in these periods, and that's why
the table is called a periodic table,
we'll see, and we'll have
class time later dedicated
exclusively to this, that there are
properties of the elements that vary.
For example, within a period, they vary in one direction.
Increasing in one period and then
repeating in the next, the
trend occurs because the elements
have periodic properties, and it is
according to these properties that they
are also organized in this table. That
is, the organization is not only by
atomic number but also by fulfilling
some other
conditions that we will see in more
Well, as I was saying, there are some groups
that have their own names. The first,
without hydrogen, is known
as the
alkali metals group, and the second is the
alkaline earth metals group. Another group
with a name is the halogens,
which are group 17, and the
noble gases, group 18. And then, in
general, the other groups are named according to the
element above them.
For example, if I want to refer to
this group, I say the boron group, or the
carbon group, which would be group
number 14. The numbering isn't here, but so, what is the purpose of
but so, what is the purpose of
using the
periodic table? What is the objective of having
the elements grouped in
this way, or also of what we are going to
see. Here are the blocks, what are
called blocks with different names.
Now we'll tell you the idea is that they are
a lot of elements that we are going to
study. Chemistry is a
very broad discipline. The periodic table
helps us to systematize
information, to have the information
organized in a certain way, so that
if I learn the
characteristics of a certain group of
elements or a certain block, then
I can identify or think about what the
behavior of an element would be depending on
where it is located. For example,
regarding the blocks, there are four, and
there is a tenth block, that one, which is the
alkali metals.
The p-block, which is this
almost square shape towards
the right of the table, the d-block, which
is the middle strip of the
transition metals, and the f-block, which is this one that's kind of off to the right of the
table, which are
metals, also the
lanthanides and the active metals. So, how can
this be useful to me?
Well, if I have to think about something in the
chemistry of phosphorus, maybe I don't have
very clear details about phosphorus, but
I know the behavior of nitrogen
or I know the behavior of sulfur, and
well, since it's next to it, I can do more. or
less reasoning because I learned some
characteristics of this block, how
that food behaves, or if it's further to the
right, the table will have a
larger or smaller radius. These are the kinds of things
that throughout the course and the
degree you get used to being able to
regarding the abundance of the
elements. Well, we see here that we have in
this list 12 elements. These are
elements that constitute 99.7%
by mass of the Earth's crust. So
imagine that from those 118—well,
several were artificial—but of
all that quantity of elements, with only
12 we would form almost 100
percent of the Earth's crust. Yes,
each of them, well, with different abundance.
abundance.
So these are the most
abundant, the most common elements, and
many of them, in fact, were the ones
that the first scientist began to study
because they were easy to find.
find.
We're talking about prehistory,
where iron was already known to have been
used. Not much was known about it,
but it was very abundant. And
then we have here another set of
elements that, on the contrary to all
those that were the 99.7% of the crust
and there were only 12. Here we have another bunch
of elements, some of which you'll see are
repeated. They are the same
elements that were important for the
Earth's crust. Some of them are
marked in this table where they are
named; that is, we tell ourselves that they are the
essential elements or bioelements. They are
elements that are precisely
essential; they will be very important to
fulfill biological functions with
metabolism, cellular functions, etc.
And notice that some seem more
obvious, like, I don't know, the calcium that we have
in our bones, or
nitrogen, oxygen that is in
nitrogenous bases, etc. But there are others that
are also metals, and perhaps one does
n't imagine that this set of
metals will be important for
biological systems. I don't know, one thinks of
manganese or iron and thinks of the
Earth's crust. Well, they are also
important for human beings. [Music]
[Music]
In this case, we have another distinction that
can be made in the periodic table, and it's like
the blocks and
the groups, with their
own names. This is the important thing to keep
in mind
from now on because we are going to
refer to this a lot. And it's the
distinction between metals,
nonmetals, and semimetals. So
basically, we can say that most
of the table is made up of metals, which
are indicated in black in
this image. Notice that the metals are the
are the
entire alkali metal group.
Hydrogen is placed
here because of its atomic weight, but remember
that it's not an alkali metal. The
entire p-block, that is, the entire middle section,
and a part
of the p-block are all metals. That is,
most of the elements. What would be, in a way,
towards the left side of the table, on the
far right, in what is, let's
say, half of the p-block,
we find the elements that
are nonmetals. In this case, they are
probably imagine them
because they are things you know, like
fluorine, chlorine, oxygen, and the
noble gases. You can imagine that they are not
metals with the characteristics of
metals. The IE has, for
example, the atmosphere of the IE.
And in the middle, we have what is
marked in pink. In this case, this
diagonal band is what we
call... Semimetals—what is a semimetal?
semimetal?
Well, it's an element that
actually has some properties
very similar to those of metals, and in
other properties, it behaves more like a
metal. This
is a behavior that
we could call intermediate between one and the
other. Depending on the characteristic I'm
observing, it will resemble a
metal more than a metal. Yes,
but well, then you'll also
hear us talk about the
metallic character, for example, of an
element. What is the metallic character of an element?
Well, that will also depend on
where it's positioned in the table. Currently, I
Currently, I
repeat, most are metals, from the
middle of the table to the left, and more
than half towards the left are metals.
Nonmetals are
relatively few, but with a
very rich chemistry despite being a small number. If
we talk about the physical state of the
elements, well, we can distinguish
the three fundamental physical states of
matter in the periodic table. That is, under
conditions, as it says here, of 25
degrees and one atmosphere—that is,
room temperature,
we could say, and atmospheric pressure—
what we see is that, precisely because
most elements are metals,
most are found in a solid state
because... All the metals,
there's one of them, mercury, which
is linked, but most metals
Then, in the non-metals section,
looking at the non-metals,
we find that we have many gases.
The noble gases, as
their name suggests, are part of the halogens.
The first halogens, nitrogen and
oxygen, are gases under these conditions.
Hydrogen is too. And you'll see that within
the halogens, the
state of matter changes as we
move through the group. We have fluorine, and of course, it's a
gas. Bromine is a liquid, and
the last two are solids. So,
bromine and mercury are the two
elements that are found in a
liquid state even in nature. In the
interactive tables here, for
example, there are two links to tables
that I know and like. You
can change the conditions,
for example, of pressure and temperature,
and it shows you the different states of
matter of the elements. In any case, it's
one of the things that's good to see.
And well, we'll see, as
I was saying, the elements, and well, they come
in their natural state as gases, and we talked
a little about Tommy Cidad. What all this was about is that
there are
some elements that have to do with
us, also aggregation, that we
will find in the form of
atoms. Atoms stand alone so
that they don't interact or form a bond,
like the noble gases. Each
of the noble gases is found in the
form of atoms, for example,
independent helium atoms,
independent neon atoms.
Other elements, some of them gases,
but also liquid bromine, helium,
etc., form what we call
discrete molecules.
What does discrete molecules mean?
It means that you can distinguish
one from another, they are like separate entities.
So the most common bases of air
come in the form of molecules and atoms.
The halogens are also all
molecules and atoms. Sulfur, for
example, in molecular form with 8 atoms,
phosphorus with four atoms, among others.
These are the most common.
Well, that is represented in these
figures. For example, in the
oxygen molecule there are two oxygen atoms, and
also here it is indicated
with these two lines that what is formed is
a double bond. It's not just any bond.
We have a question, let's see, Santiago [Music]
[Music]
yes We say the microphone
called
discrete molecules or anything that's
defined as a discrete entity, which
means that it's distinguishable from one
another, that is, as separate entities. For example,
if I were to observe them closely
and see, see, the molecules... The separated ones,
this is in contrast to what,
for example, we're going to see now,
are solids [Music]
[Music]
that form three-dimensional networks where you ca
n't distinguish one from another.
Now, now you'll realize the difference.
difference.
Well, we have other elements that are what are
called solids, but
molecular ones. Instead of forming
discrete entities, excuse me, they form networks
where there are many, infinite atoms
organized in a certain way.
For example, here are the ones in the other
post about carbon. They are different from each
other because they have different
structures in the solid state.
One is diamond, behind it graphite,
another is... this is a case of
fullerenes, an example. Yes, but what I'm getting at is
that each of these atoms is
surrounded by others of the same kind and in
certain arrangements, but there are no
associations, for example, between pairs,
like I just mentioned, of four atoms that can be
distinguished from one another. Instead, this
is infinite and it's all the same; you can't
We also have metallic solids, that
is, those that make up the majority of the
periodic table, which are metals, which
also form networks, and in this case, it's not...
We weren't talking about
discrete entities here; it's precisely the
fact that they are networks that can take
different forms. Here,
two types of networks are shown: a
public house and this hexagonal one.
In metals, all the atoms are organized in these
networks one
after the other. For different
metals, there will be a different arrangement.
And well, this is the way
we find solids in nature.
I mentioned something in the
other post about
carbon. Well, I didn't explain
exactly what that means the other day,
but precisely these are—excuse me—
different ways in which the atoms
that constitute the network of the
sun are organized in the solid state. And the example of carbon and
diamond is perhaps the best known
to you,
and visually it's tremendous. It's not
very easy to see; I mean, I've never seen a
diamond up close in a shop window.
But the merit and transparency of the
diamond has nothing to do with
what carbon is. Graphite, which is carbon, is what
pencils are made of, is
black and practically opaque. This, or at
least very little shine in
comparison without it, and well, this is
due precisely to how the
carbon is arranged in each of them. In
graphite, it forms a network of this style with
an interconnected organization.
This gives the
diamond characteristics that make it so
transparent, for example, and give it that
shine in the light. Graphite carbon,
however, forms sheets of sheets where
the carbon is organized in hexagons, and
these sheets, in turn,
require little force to slide
over one another, and that is what allows us,
for example, to use a
pencil or charcoal when
But they are not the
only ones found in solids; there are
others also known
to you, so without thinking too much,
but oxygen has two,
which are precisely diatomic oxygen,
which is the oxygen we breathe,
and this
molecule here, or three, which is
ozone. The ozone molecule is the one
that in our section of the sky
has a coefficient. Ozone,
in turn, is something that
photocopiers give off—that smell. What do you smell
in photocopiers? Is it an
the mole minister, one thing: no, because an
isotope would be, let's say, an isotope of
oxygen would be oxygen formed with
oxygen atoms that have a greater number
of neutrons.
Here we're not focusing on that, because
the same oxygen atom with a
certain number of protons and
neutrons can form
atomic or triatomic molecules called ozone.
And well, then also in metals there are
different ones, for example, there's
the case of tin, but it happens with
several metals, with iron too, that
have different solid phases, and there are
different ones because they are called
alpha, beta, gamma, and so on. And it also
has to do with the organization of the
atoms in the lattice of the solid, and each
of them has different properties.
This is regarding
the properties of the metal, I mean.
Let's talk then about what a compound is,
and we'll wrap up with this part. A
compound, then, is a substance that
is formed by the chemical union of two
or more elements, and again, in
fixed and defined proportions.
When we say "united" in chemistry, we are
talking about a chemical bond. of some kind,
kind,
which we'll see later, all the types of
bonds that exist, we'll see them during
a course, but then there's a
chemical union of atoms of
elements, and the proportions are
fixed, they're unique. Take
sugar, for example. Sugar has a
certain number of atoms of each element,
and if I change them, I'm changing the
formula, I'm changing the composition, and
therefore I'm talking about a
And
if it's a substance, we
separate the instances into
elements, which are the simplest substances
that exist, and compounds, which
So, precisely, a
compound is formed by
elements, meaning we couldn't break it down
into its elements by
chemical methods, for example, by a
chemical reaction.
But at the same time, a compound doesn't
necessarily have to have
similar characteristics to the
elements that form it. It's not like a
mixture, where if I mix two components,
well, the mixture has
characteristics of air. Here, the
compound is something totally
different with a
different behavior. If we can imagine
the water molecule, for example, which is
n't something that always comes to mind, and
well, in water, the water we drink, the
water we know, it doesn't have a
Similar behavior to that of
hydrogen and oxygen gases separately, and
yet they are the elements that form it,
but this is basically a very
important difference with what is a mixture.
So, we are going to
refer to molecules, which will be of
elements, as we saw that there are elements,
molecular forms, and atomic or
compound forms, and we are also going to refer
to ions, which can be cations or anions.
These ions are the species that are
charged, that somehow lost
and gained electrons, and that makes them have
a charge. If the charge is positive, we
have called them ions, and if the
charge is negative, we will call them anions.
As a result of a chemical reaction,
not a chemical change in a
molecule, ions can be formed, for example.
example.
So, those are the things, the terms
that you have to get
used to and start getting used to.
Now, we are going
to look at some nomenclature.
We are going to see how compounds are
formulated and how they are named. Yes,
in principle, we will see how to write the
formulas, which is a little simpler than naming them.
naming them.
So, I'll tell you that there are two types of
formulas that we are going to
refer to. This is what we call the
molecular formula or real formula, and
another is what is called the empirical formula
or empirical formula. The
difference between them is that the
molecular or real formula indicates
the composition of the compound, that is, what
elements form it, and the proportion
in which they are found. It
also indicates the molecular weight, in the
case of a molecule, in the sense
that it says how many atoms of each element
constitute it, not only the
proportion but also how many atoms. For
example, this is the case of
hydrogen peroxide. In hydrogen peroxide,
there are two hydrogen atoms and two
oxygen atoms. This is its molecular formula.
If I write the empirical formula or the
simplest formula, what is the difference? Well, in the simplest formula,
Well, in the simplest formula, the total number of atoms doesn't have to be given,
the total number of atoms doesn't have to be given, only the proportion in which
only the proportion in which the constituents are found. So,
the constituents are found. So, for hydrogen peroxide, the empirical formula (
for hydrogen peroxide, the empirical formula (
H) – one hydrogen atom and one oxygen atom – doesn't mean that this is the
doesn't mean that this is the compound because we know that the
compound because we know that the compound is this other one that has two oxygen
compound is this other one that has two oxygen atoms. But this is the
atoms. But this is the empirical formula because, for example, it can happen
empirical formula because, for example, it can happen that... Based on certain tests
that... Based on certain tests one conducts to determine the
one conducts to determine the composition of a substance, one might
composition of a substance, one might conclude that the ratio between the
conclude that the ratio between the two atoms is one to one. However,
two atoms is one to one. However, other studies are needed to
other studies are needed to gather more information and confirm its
gather more information and confirm its form.
There are cases where they differ, such as in hydrogen peroxide
in hydrogen peroxide or, in this case,
or, in this case, nitrogen oxide. The
nitrogen oxide. The real formula is distinguished from the empirical formula, and
real formula is distinguished from the empirical formula, and sometimes they coincide. This is because in
sometimes they coincide. This is because in some substances, where there is
some substances, where there is an atom, a number of atoms—or rather,
an atom, a number of atoms—or rather, a type of atom—that has a
a type of atom—that has a coefficient of 1, the simplest formula will
coefficient of 1, the simplest formula will always be written with the
always be written with the lowest coefficient, meaning
lowest coefficient, meaning whole numbers, which is 1. Therefore,
whole numbers, which is 1. Therefore, in formulas of this type, the
in formulas of this type, the empirical and molecular formulas will coincide
empirical and molecular formulas will coincide because we won't write fractions
because we won't write fractions here, like the atomized oxygen. So,
here, like the atomized oxygen. So, the case of water coincides with the case of nitrogen oxide.
the case of water coincides with the case of nitrogen oxide.
Later in the course, you will work extensively with the empirical or simplest formula.
extensively with the empirical or simplest formula. Now, since we are going to talk about
Now, since we are going to talk about a mixture, we will focus more on this.
a mixture, we will focus more on this. But what's happening is that there's
But what's happening is that there's one thing I want you to know about
one thing I want you to know about all these formulas I've
all these formulas I've written. I always write the
written. I always write the ion first, in the case of a compound, or the
ion first, in the case of a compound, or the most electronegative element, or rather, the
most electronegative element, or rather, the most electropositive element,
most electropositive element, and secondly,
and secondly, the most electronegative element
the most electronegative element of those that make up the compound. For example,
of those that make up the compound. For example, in the case of
in the case of hydrogen peroxide, hydrogen is the least
hydrogen peroxide, hydrogen is the least electronegative and oxygen the most
electronegative and oxygen the most electronegative. It's written last. You
don't see this, for example, in a typical compound that I'm sure everyone knows,
compound that I'm sure everyone knows, which is sodium chloride.
which is sodium chloride.
I say chloride first and then sodium, but the formula isn't sodium chloride.
Here in this case, we're talking about two ions with more or less one charge. Let me
two ions with more or less one charge. Let me give you another example: another ion that I
give you another example: another ion that I know isn't monatomic like sodium;
know isn't monatomic like sodium; in fact, it has several atoms, which is
in fact, it has several atoms, which is ammonium.
ammonium. The formula is written the same way. Or, sorry,
The formula is written the same way. Or, sorry, we have another chloride here, which is
we have another chloride here, which is sulfur chloride. In this case, we're not
sulfur chloride. In this case, we're not talking about a cation or a union, but
talking about a cation or a union, but about two nonmetals where the least
about two nonmetals where the least electronegative, which is the Sulfur is
electronegative, which is the Sulfur is written first, and chlorine,
written first, and chlorine, and the same happens if we have
and the same happens if we have more complicated hyphens in their structure, like
more complicated hyphens in their structure, like sulfate,
sulfate, sodium sulfate, sodium sulfide. You
sodium sulfate, sodium sulfide. You see, they both have sulfur,
see, they both have sulfur, but they form different entities with
but they form different entities with different names. Another thing you have to keep in
different names. Another thing you have to keep in mind, or that you'll
mind, or that you'll see in the formulas, is this other thing
see in the formulas, is this other thing written here in green. Well, this
written here in green. Well, this is the formula for a salt, which is
is the formula for a salt, which is copper sulfate, yes, but it's also
copper sulfate, yes, but it's also represented with 1.5 water molecules. What does
represented with 1.5 water molecules. What does this mean? These are what are called
this mean? These are what are called hydrates. That is, in this case, it's a
hydrates. That is, in this case, it's a solid in which, in addition
solid in which, in addition to having sulfates (copper regions),
to having sulfates (copper regions), there are five
there are five water molecules for each one in the crystal lattice. That's
water molecules for each one in the crystal lattice. That's another thing that's also
another thing that's also represented in the formulas of
represented in the formulas of compounds.
So, back to discrete molecules. To
back to discrete molecules. To write discrete molecules in the
write discrete molecules in the formula, the molecular or real formula is always used
formula, the molecular or real formula is always used
because we can write it [Music].
[Music]. When we write polymers, there can be
When we write polymers, there can be differences because what would be the
differences because what would be the formula, for example, coincides, sorry, in
formula, for example, coincides, sorry, in the molecules. They coincide,
the molecules. They coincide, in these examples, with the minimum, not with
in these examples, with the minimum, not with The simplest formula,
The simplest formula, as I mentioned, isn't always the case.
as I mentioned, isn't always the case. Polymers, for example, can have
Polymers, for example, can have situations where the
situations where the empirical or simplest formula is one thing, but
empirical or simplest formula is one thing, but
in reality, the substance is something else. This happens with phosphorus oxide,
with phosphorus oxide,
which has this formula, but in reality, it's known to have a structure like this:
in reality, it's known to have a structure like this: four
four phosphorus atoms surrounded by ten oxygen atoms, forming this
phosphorus atoms surrounded by ten oxygen atoms, forming this structure shown here. So,
structure shown here. So, the actual entity doesn't always follow
the actual entity doesn't always follow a specific
a specific formula; it can be something else. The same applies
formula; it can be something else. The same applies to polymers.
to polymers. Something similar happens with
Something similar happens with sulfur, which, as I said, forms molecules.
sulfur, which, as I said, forms molecules. Sulfur forms
Sulfur forms different types of molecules. Here, the one with
different types of molecules. Here, the one with
seven atoms is drawn, but it also exists with six or eight. When you write
six or eight. When you write sulfur as an element, you end up
sulfur as an element, you end up writing "
writing " nothing." It doesn't necessarily indicate
nothing." It doesn't necessarily indicate which molecule you're referring to,
which molecule you're referring to, depending on the conditions.
For example, in the formula for a bond, we write "S" when it forms a bond.
we write "S" when it forms a bond. Writing a bond in a reaction will depend on the
Writing a bond in a reaction will depend on the specific conditions
and the purpose of the bond. Empirical formulas are used to name
Empirical formulas are used to name ionic substances,
ionic substances, ionic compounds that are organized in infinite lattices. A
ionic compounds that are organized in infinite lattices. A
typical example is sodium chloride. What is a sodium chloride lattice? Well,
a sodium chloride lattice? Well, the positive sodium ions (in
the positive sodium ions (in this case, green) and the negative chloride ions
this case, green) and the negative chloride ions alternate, one with the other,
alternate, one with the other, positive with negative, in a lattice
positive with negative, in a lattice that, in all three directions, is an
that, in all three directions, is an infinite lattice. So why do I use what I
infinite lattice. So why do I use what I call the empirical formula? Well,
call the empirical formula? Well, because I don't write "infinite sodium" or "
because I don't write "infinite sodium" or " infinite chloride."
infinite chloride." And this, I repeat, is what
And this, I repeat, is what distinguishes it from
distinguishes it from discrete molecules. Because if I could
discrete molecules. Because if I could shrink down and stand here and
shrink down and stand here and look around, I wouldn't distinguish pairs
look around, I wouldn't distinguish pairs of sodium and chloride ions,
of sodium and chloride ions, one different from the other; they are all
one different from the other; they are all equivalent to each other. That's why it's an
equivalent to each other. That's why it's an infinite lattice, organized regularly with
infinite lattice, organized regularly with the lines connecting them. So,
the lines connecting them. So, in these cases, for
in these cases, for ionic compounds, we use
ionic compounds, we use their formulas. And we'll
see, then, how the compounds are named, how we write the
the compounds are named, how we write the names, and how we read the names.
names, and how we read the names. These formulas, then,
These formulas, then, contrary to the
contrary to the reversed formula, are how we have to
reversed formula, are how we have to name them. That is, if I write e-cl
name them. That is, if I write e-cl referring to the salt sodium chloride, I
referring to the salt sodium chloride, I name it in reverse: first, I
name it in reverse: first, I name the ion chloride, and then I name
name the ion chloride, and then I name the cation sol. And if they were nonmetals, we would
the cation sol. And if they were nonmetals, we would first name the element with the
first name the element with the most negative electron, and then the one with the fewest
most negative electron, and then the one with the fewest negative electrons.
negative electrons. Now, there are rules for naming,
Now, there are rules for naming, precisely so that
precisely so that people don't just name things however they want, so that everyone doesn't name
people don't just name things however they want, so that everyone doesn't name
the different compounds however they please. So, this is something that was used at one time
something that was used at one time in familiar
in familiar or common names; some of them are still used
or common names; some of them are still used today for well-
today for well- known substances, such as
known substances, such as water and ammonia. These are
water and ammonia. These are common names that are accepted. But
common names that are accepted. But at one time, let's say to talk about
at one time, let's say to talk about this compound, which is
this compound, which is iron chloride, we would have said
iron chloride, we would have said ferric chloride. That nomenclature is
ferric chloride. That nomenclature is discouraged. Now, we try
discouraged. Now, we try to use systematic nomenclature, which
to use systematic nomenclature, which is the one given by the IUPAC, which has
is the one given by the IUPAC, which has certain Rules that we're going to see now are what
certain Rules that we're going to see now are what prevent confusion
prevent confusion when speaking, writing, and reading chemistry, and allow us
when speaking, writing, and reading chemistry, and allow us all to communicate in the same
all to communicate in the same language. There's
language. There's also
also Stock nomenclature, which indicates the
Stock nomenclature, which indicates the oxidation state of the metal in
oxidation state of the metal in parentheses.
parentheses. So, to refer to this
So, to refer to this compound, we would call it
compound, we would call it iron(III) chloride because the oxidation state of iron here is
iron(III) chloride because the oxidation state of iron here is 3. There's also
3. There's also iron(II) chloride,
iron(II) chloride, and this same compound, using Stock
and this same compound, using Stock nomenclature, would be
nomenclature, would be called iron(III) chloride.
called iron(III) chloride. That's the one we're
That's the one we're going to learn to use. It doesn't mean
going to learn to use. It doesn't mean that using it is wrong, but we're going
that using it is wrong, but we're going to learn more about it, since it's the one we
to learn more about it, since it's the one we use most often. Some substances
use most often. Some substances still use common names, which
still use common names, which are accepted by Stock nomenclature. So,
are accepted by Stock nomenclature. So, basically, we're going to see the
basically, we're going to see the nomenclature of binary and non-binary compounds. Binary compounds have
nomenclature of binary and non-binary compounds. Binary compounds have two elements, and non-
two elements, and non- binary compounds have three or more elements,
binary compounds have three or more elements, which is a bit more complicated when there are
which is a bit more complicated when there are more elements.
So, things we need to know before we start
things we need to know before we start naming:
naming: we're going to use prefixes and suffixes.
we're going to use prefixes and suffixes. For example, use prefixes that
For example, use prefixes that indicate the proportion of elements
indicate the proportion of elements between them. An example of
between them. An example of iron chloride is iron(III). Well, that trick I
iron chloride is iron(III). Well, that trick I added to the word chloride is
added to the word chloride is a multiplying prefix. I
a multiplying prefix. I mean, I'm going to use these terms, these
mean, I'm going to use these terms, these prefixes, to indicate how many atoms of
prefixes, to indicate how many atoms of an element there are in a molecule. For
an element there are in a molecule. For example, iron(III) chloride,
example, iron(III) chloride, tetra if there are 4, 3 if there are 5, and so
tetra if there are 4, 3 if there are 5, and so on.
on. Mono when there is only one. Often, the
Mono when there is only one. Often, the mono is omitted from the names.
mono is omitted from the names. [Music]
[Music] When it's a student of the comic,
When it's a student of the comic, sometimes it's not written
sometimes it's not written
when there's no room for confusion.
So here, for example, all these nitrogen oxides, I could
nitrogen oxides, I could name them using the YouTube nomenclature
name them using the YouTube nomenclature without having much of an idea of what
without having much of an idea of what oxidation state nitrogen has in each
oxidation state nitrogen has in each case or anything. I mean, just knowing
case or anything. I mean, just knowing that this is 1, 18, or 24, I can name
that this is 1, 18, or 24, I can name these directly by oxidation state and do
these directly by oxidation state and do the calculation. I mean, I can simply
the calculation. I mean, I can simply read here "oxide" because there are 5
read here "oxide" because there are 5 nitrogen atoms,
nitrogen atoms, following the Impact nomenclature, and that's it. I do
following the Impact nomenclature, and that's it. I do n't have to think
n't have to think much more. It wasn't there before, and well,
much more. It wasn't there before, and well, the idea is precisely to make it easier and also for us
the idea is precisely to make it easier and also for us all to be consistent and
all to be consistent and call them the same thing.
how we do it when there are more than 10 to start going. There are more. There aren't any more
to start going. There are more. There aren't any more prefixes. I didn't put them because it wasn't
prefixes. I didn't put them because it wasn't necessary to fill the sheet, but there is
necessary to fill the sheet, but there is one from each cellar, and so on, 11-12.
one from each cellar, and so on, 11-12.
Well, then there are other
there are other terms that are used according to the
terms that are used according to the oxidation state because sometimes we have to
oxidation state because sometimes we have to mention the oxidation state of
mention the oxidation state of one of the elements. More
one of the elements. More than mentioning this oxidation, we
than mentioning this oxidation, we mention that the oxidation state
mention that the oxidation state constitutes, for example, a hyphen.
constitutes, for example, a hyphen. So this happens for typical
So this happens for typical anions. There are different anions that will be
anions. There are different anions that will be formed according to the
formed according to the oxidation state of the element that
oxidation state of the element that constitutes them. So, non-atomic anions have
constitutes them. So, non-atomic anions have
two suffixes added to the end of the element's name to indicate
of the element's name to indicate that they are anions. For example,
that they are anions. For example, chloride, for pure anions, or the
chloride, for pure anions, or the suffix -ide, as in oxide, are
suffix -ide, as in oxide, are indicators that these elements have
indicators that these elements have become bonds. That is, chlorine has
become bonds. That is, chlorine has become a bond, it's called
become a bond, it's called chloride,
and oxygen, if it becomes an anion, it's called an oxide. Yes.
called an oxide. Yes. For polyatomic planes, or options
For polyatomic planes, or options that have oxygen in their structure, it's
that have oxygen in their structure, it's no longer like a single
no longer like a single element, but rather
element, but rather several elements that form these planes, whether they are
several elements that form these planes, whether they are their offspring, for example, all of this
because I say that I'm referring to the oxidation state. Well, because
oxidation state. Well, because the element, depending on its
the element, depending on its oxidation state, will give you a name,
oxidation state, will give you a name, in this case, nitrogen will be
in this case, nitrogen will be called nitrate and nitrite.
And sometimes, to distinguish between them, we find
distinguish between them, we find many similar ones, so
many similar ones, so we have to use these prefixes,
we have to use these prefixes, which
which are added to the names in addition
are added to the names in addition to the suffixes. Now, let's look at some
to the suffixes. Now, let's look at some examples so that it doesn't overwhelm us. So,
examples so that it doesn't overwhelm us. So,
names of common monatomic ions, what I was saying, those that
end in -ide, the halogens,
halogens, basically these are... If all the
basically these are... If all the halogens, for example, whose
halogens, for example, whose name isn't fluorine,
name isn't fluorine, are called chlorides, chlorine chloride,
are called chlorides, chlorine chloride, bromine bromide, we
bromine bromide, we have hydrogen hydride, which is
have hydrogen hydride, which is hydrogen with an anion, and some
hydrogen with an anion, and some that are non-metals, also a little
that are non-metals, also a little different, sulfide, phosphorus nitride,
different, sulfide, phosphorus nitride, which may not be so familiar, and the
which may not be so familiar, and the exception is oxide, well, there are
exception is oxide, well, there are the two endings -o-
the two endings -o- and we have this,
and we have this, but the list isn't infinite,
but the list isn't infinite, basically these are, and there are some more that you
basically these are, and there are some more that you have to learn. Yes, you're
have to learn. Yes, you're so thoughtful that you ask, you have to
so thoughtful that you ask, you have to know them, you have to learn them today,
know them, you have to learn them today, but you will learn them
but you will learn them throughout the classes, and what you have to
throughout the classes, and what you have to do to learn this is practice
do to learn this is practice and do exercises and exercises and
and do exercises and exercises and exercises of nomenclature and other
exercises of nomenclature and other types, and they will end up sticking in your
types, and they will end up sticking in your head. What you have to do is
head. What you have to do is pay attention when writing a
pay attention when writing a formula, what is this called, and so on, and it will stick.
formula, what is this called, and so on, and it will stick.
Some common polyatomic compounds, which are also, let's say,
also, let's say, relatively small, which also
relatively small, which also end in
end in a globular shape, we have hydroxide, for
a globular shape, we have hydroxide, for example, the Peroxide has that
example, the Peroxide has that ending, and then there are others that
ending, and then there are others that have other names, they are the
have other names, they are the common names, like cyanide, well, they
common names, like cyanide, well, they also end in -1 or some complex hyphens
also end in -1 or some complex hyphens because later on you are going to
because later on you are going to work with them. And here
work with them. And here we have
we have the users, I was telling you,
the users, I was telling you, elements that have oxygen, which already
elements that have oxygen, which already have the ending that is used, which
have the ending that is used, which is -ito. If,
is -ito. If, for example, we have the first ones on the
for example, we have the first ones on the list, we have sulfate and sulfite here.
list, we have sulfate and sulfite here. What is the difference between them?
What is the difference between them? This is the formula,
This is the formula, and looking at a formula, you can see that they have
and looking at a formula, you can see that they have sulfur, they have the
sulfur, they have the same negative charge -2, but there are
same negative charge -2, but there are different numbers of oxygen atoms
different numbers of oxygen atoms here, 4 and 3. What does this
here, 4 and 3. What does this really mean? If I were to look at the
really mean? If I were to look at the oxidation numbers of the elements, I have a
oxidation numbers of the elements, I have a different oxidation number in this
different oxidation number in this sulfur than in this other one. That's why, to
sulfur than in this other one. That's why, to have the same charge, I have a different
have the same charge, I have a different number of oxygen atoms. The one with
number of oxygen atoms. The one with more I call apto, and the one with
more I call apto, and the one with less I call hito. The same happens with
less I call hito. The same happens with nitrate and nitrite. The one with more
nitrate and nitrite. The one with more oxygen is apto, and the one with less is
oxygen is apto, and the one with less is hito. Yes.
[Music] There were some cases that I told you about.
There were some cases that I told you about. Sometimes you need to add prefixes, like "
Sometimes you need to add prefixes, like " dog" and "hiccup." When that happens, well,
dog" and "hiccup." When that happens, well, when I suddenly have more than two or more
when I suddenly have more than two or more hyphens to distinguish with the same
hyphens to distinguish with the same elements—in sulfur there are two, in
elements—in sulfur there are two, in micronitrates there are two—but when it comes
micronitrates there are two—but when it comes to halogens, in this case with
to halogens, in this case with chlorine, forming options,
chlorine, forming options, we're going to have four species because
we're going to have four species because chlorine has several
chlorine has several oxidation states and therefore forms four
oxidation states and therefore forms four different options: this one
different options: this one with four oxygen atoms,
with four oxygen atoms, then 3, 2, and 1. They all maintain the same
then 3, 2, and 1. They all maintain the same charge but have different
charge but have different oxygen atoms. That's not what they're called. Well,
oxygen atoms. That's not what they're called. Well, besides chlorate and chlorine, which would be
besides chlorate and chlorine, which would be analogous to what we see here,
analogous to what we see here, we have to add two names. How do we do it?
we have to add two names. How do we do it? How do we transform the names
How do we transform the names to have four ions? Well, to chlorate, the one that
to have four ions? Well, to chlorate, the one that ended in -act, we add the
ended in -act, we add the prefix -hypo, meaning
prefix -hypo, meaning above or below. So,
above or below. So, chlorate, which had three atoms,
chlorate, which had three atoms, perchlorate has four.
And on the other hand, to the one that ended in -itho, for chlorine, I add the prefix -hypo,
for chlorine, I add the prefix -hypo, meaning below.
meaning below. So, the one with only one
So, the one with only one oxygen atom ends up Calling it hypochlorite
sounds like a tongue twister, it's not that serious, you'll learn it. You'll see that if there
that if there aren't that many cases, they call it that, and if it's
aren't that many cases, they call it that, and if it's repetitive, it's always the same, always the same. Yes, let's see, I don't know
repetitive, it's always the same, always the same. Yes, let's see, I don't know
who's first, Esteban Efe.
A question: if we don't know if, for example, chlorate is
for example, chlorate is chlorine 3- and not
chlorine 3- and not 2-, as a difference in position, you don't
2-, as a difference in position, you don't
in a way, let's say if you see a
if you see a list of 4, it will be
list of 4, it will be ordered if the one with more oxygen
ordered if the one with more oxygen is the one with less, and so on with the names. That's how
is the one with less, and so on with the names. That's how we know,
we know, this is always the same. That is, if tomorrow I
this is always the same. That is, if tomorrow I write to you, I change the chlorine to
write to you, I change the chlorine to bromine, there I put the names with bromine,
bromine, there I put the names with bromine, no, that is, it's not that one has to
no, that is, it's not that one has to distinguish, it's the one with less oxygen,
distinguish, it's the one with less oxygen, that's always the hypo, and the one
that's always the hypo, and the one with more is the hypo,
with more is the hypo, in this order for the names, that's what
in this order for the names, that's what I mean. Thanks, Rafa, you're welcome. Let's see,
I mean. Thanks, Rafa, you're welcome. Let's see,
here I know the prefix, active and without creating, it has sulfur. The "uncle"
active and without creating, it has sulfur. The "uncle" is the profile, as sulfur indicates.
is the profile, as sulfur indicates. So, for example, this John, that It was
So, for example, this John, that It was cyanide, sorry, yes, angiotensin,
cyanide, sorry, yes, angiotensin, sorry, it's born with oxygen and when it
sorry, it's born with oxygen and when it requires it, it doesn't change, it suffers, it's called ocean,
and now I have a question from someone named p and 77 music,
named p and 77 music, and
I wanted to ask you a question, more than anything, for example, just to give you an example,
anything, for example, just to give you an example, carbonate, for example, we already
carbonate, for example, we already know why they would make the table I
know why they would make the table I want, 32 - if I see CO2
want, 32 - if I see CO2 2 - I already know that it would be with the ending -ite,
2 - I already know that it would be with the ending -ite, but to know perfectly well if what
but to know perfectly well if what happens is that there isn't one,
happens is that there isn't one, but why don't they all exist, you understand,
but why don't they all exist, you understand, if even your reasoning isn't
if even your reasoning isn't correct, but no, no, not for all the
correct, but no, no, not for all the elements, Joshua Nyon, it's like that, but if it
elements, Joshua Nyon, it's like that, but if it existed, the name would be, so
existed, the name would be, so thank you, well,
thank you, well,
then these again, I have to learn them, if we have to learn them,
learn them, if we have to learn them, how do
how do you have to learn them, however you think is best, your method for
you have to learn them, however you think is best, your method for learning names, for I think the
learning names, for I think the best thing is to do everything you can and
best thing is to do everything you can and eventually I will come in if
eventually I will come in if you pay attention, obviously
the cations are named more easily because except for all these
except for all these polyatomic cations, which are these that are Here they are
polyatomic cations, which are these that are Here they are called ammonium font, I, the sound is,
called ammonium font, I, the sound is,
these have a chair, what happens, do you have another question, maybe from the
another question, maybe from the Kabylie, I wanted to finish the idea, thank you, I was
Kabylie, I wanted to finish the idea, thank you, I was n't going to tell you, I mean, I'm already here,
n't going to tell you, I mean, I'm already here, the word associate, these
the word associate, these polyatomic cations, which are these with their
polyatomic cations, which are these with their own name, let's say, and in the rest they are
own name, let's say, and in the rest they are named like the name of the element,
named like the name of the element, Sofia, tell me, I did
n't want to ask if they are listening to me,
bicarbonate, exactly, it's the same, but in reality, according to the IUPAC, we should
reality, according to the IUPAC, we should call it hydrogen carbonate, which we
call it hydrogen carbonate, which we call bicarbonate,
well, so the cations, I call them the cations that simplify life
the cations that simplify life because when they want to refer to a
because when they want to refer to a metal they simply say cation x with the
metal they simply say cation x with the name of the metal, for example, cobalt 2 with a
name of the metal, for example, cobalt 2 with a high time 3 when I have two
high time 3 when I have two different oxidation states, one over
different oxidation states, one over two, the silver, in
two, the silver, in reality I can write the
reality I can write the oxidation number, but in reality silver is
oxidation number, but in reality silver is the only one that has it, so it could be
the only one that has it, so it could be omitted, you will also see names like
omitted, you will also see names like this one here, which is q, but so
this one here, which is q, but so Kubrick or not, public, those are
Kubrick or not, public, those are the common names, the
the common names, the previous nomenclature is the one we made, that We don't
previous nomenclature is the one we made, that We don't always use it; you'll find some
always use it; you'll find some teacher who calls it Kubrick chloride
teacher who calls it Kubrick chloride or, for example, copper chloride 2.
or, for example, copper chloride 2. Well, I don't mean an old teacher,
then, as we said, how do we name them separately?
name them separately? Now, as I say, the name of
Now, as I say, the name of everything is precisely... well, I have to
everything is precisely... well, I have to see how many of a certain element I
see how many of a certain element I have in the molecule and how many of the
have in the molecule and how many of the cations, and I add the
cations, and I add the necessary prefixes. So, the same
necessary prefixes. So, the same example from today, in this case, it's Dimitrov oxide,
example from today, in this case, it's Dimitrov oxide, because I have five oxygens, two
because I have five oxygens, two nitrogens,
nitrogens, this is chlorine oxide. In this case, they are
this is chlorine oxide. In this case, they are all metals, so I name them after the
all metals, so I name them after the least electronegative element.
least electronegative element.
If it were a metal with one metal, for example, a metallic oxide, I
could also use the nomenclature. I don't use the oxidation state
don't use the oxidation state indicated in this oxidation. So,
indicated in this oxidation. So, there's a compound, for example, this, every two atoms, that
there's a compound, for example, this, every two atoms, that is, two potassium atoms with one oxygen atom.
is, two potassium atoms with one oxygen atom. I could call this
I could call this potassium oxide or potassium chloride. What
potassium oxide or potassium chloride. What happens in this case is the only one there because
happens in this case is the only one there because potassium atoms are the most common formations. 1. So,
potassium atoms are the most common formations. 1. So, I can actually omit this
I can actually omit this and say potassium oxide, and it's understood the
and say potassium oxide, and it's understood the same way; it doesn't lead to confusion.
same way; it doesn't lead to confusion. Saying potassium oxide one
Saying potassium oxide one is also redundant; I can omit the one
is also redundant; I can omit the one because this is the only possible oxidation state.
because this is the only possible oxidation state.
Then you might find some old books with this nomenclature, like they
some old books with this nomenclature, like they call it "Emmy potassium oxide," "This is ski," "
call it "Emmy potassium oxide," "This is ski," " iron oxide." In the case of
iron oxide." In the case of iron oxide, all these things are
iron oxide, all these things are no longer used, but I'm showing them to you
no longer used, but I'm showing them to you because you might find them
because you might find them written somewhere. And tell me,
written somewhere. And tell me,
really wanted to ask you, when you said potassium oxide, is it possible to
you said potassium oxide, is it possible to specify it? Is it necessary? If so, why not? In
specify it? Is it necessary? If so, why not? In fact, it's fine to just
fact, it's fine to just say potassium oxide because
say potassium oxide because potassium only forms +1 cations,
potassium only forms +1 cations, so there's only one possible potassium oxide.
so there's only one possible potassium oxide.
The distinction has to be made when there are other types, like in the case of iron.
there are other types, like in the case of iron. At the beginning, it can have iron 2 or
At the beginning, it can have iron 2 or iron 3. So, in that case, I
iron 3. So, in that case, I have to indicate which one it is.
have to indicate which one it is.
This mica, the one with the hand raised, is the same capacity.
I don't change the name.
Why can't it be Esteban? The import option
import option can be, but it's not necessary.
Yes, it could also be monoxide. One could use the prefix on
One could use the prefix on each of the elements,
each of the elements, but they are omitted in cases
but they are omitted in cases where there is no confusion.
Well, more complicated examples, like here we have
here we have aluminum chlorine. The "mono" is also in
aluminum chlorine. The "mono" is also in parentheses. It's not necessary to say "the tri"
parentheses. It's not necessary to say "the tri" because the "tri"
because the "tri" refers to the number.
refers to the number. The chlorite species. All of this that is
The chlorite species. All of this that is written in parentheses is that. Don't
written in parentheses is that. Don't forget. If I put here without
forget. If I put here without parentheses "aluminum chlorine oxygen 23," it
parentheses "aluminum chlorine oxygen 23," it seems as if I were saying that there are 23
seems as if I were saying that there are 23 atoms.
For example, in this other case, we have monohydrogen phosphate. What does
monohydrogen phosphate. What does all this refer to?
all this refer to? And why are there two? Remember, there
And why are there two? Remember, there are two ammonium phosphates.
are two ammonium phosphates. All of this "t" refers to this
All of this "t" refers to this hyphen, which is helium hydrogen phosphate.
hyphen, which is helium hydrogen phosphate. Monohydrogen phosphate. Why?
Monohydrogen phosphate. Why? Because we have
Because we have a hydrogen atom here.
And well, what is the example of the hydrated species that I showed you today?
hydrated species that I showed you today? Copper sulfate. At this point,
Copper sulfate. At this point, we have copper sulfate here. Again, the
we have copper sulfate here. Again, the wall in parentheses because it would be mono,
wall in parentheses because it would be mono, but it omits copper sulfate pentahydrate
but it omits copper sulfate pentahydrate as we normally call it,
as we normally call it, but the IUPAC, of course, is now
but the IUPAC, of course, is now recommending that it be written like this:
recommending that it be written like this: copper sulfate water 15, as if saying one of
copper sulfate water 15, as if saying one of its copper five water photos. The
its copper five water photos. The reality is that we haven't gotten used to it
reality is that we haven't gotten used to it and we use this all the
and we use this all the time, but this would be the correct IUPAC name.
time, but this would be the correct IUPAC name.
Oh, sorry, I have a question before continuing, if we're already at the end. With
continuing, if we're already at the end. With apologies, hello.
apologies, hello. If the missing diamond, I'm asking because the
If the missing diamond, I'm asking because the day is in parentheses
day is in parentheses because it's not really. Again, it
because it's not really. Again, it can be omitted in the sense that
can be omitted in the sense that ammonium is also a hyphen,
ammonium is also a hyphen, a single ammonium ion exists, NH4 with a positive charge.
a single ammonium ion exists, NH4 with a positive charge.
If it were a metal, iron again, I would have to say how many irons
would have to say how many irons can come into play, iron 3, but
can come into play, iron 3, but in this case, it's the only one. If I put
in this case, it's the only one. If I put this ring that has a charge of -2 to
this ring that has a charge of -2 to put ammonium, I have to compensate with
put ammonium, I have to compensate with 2 ammonium, I have no other option.
And the last thing, and we're finished, is how in turn we even name the... there are no ions
turn we even name the... there are no ions with cations But what happens when
with cations But what happens when we name acids? When we name them,
we name acids? When we name them, the names change. So, if everything we saw
the names change. So, if everything we saw here—
here— the sulfate, well, all those elements
the sulfate, well, all those elements at the levels of the table—were
at the levels of the table—were combining with hydrogen and
combining with hydrogen and therefore forming acids, I know, if the formula were
therefore forming acids, I know, if the formula were hydrogen + 1, we
hydrogen + 1, we have to change the name. The
have to change the name. The nomenclature of acids is different from that
nomenclature of acids is different from that of salts.
of salts. How different it is is
How different it is is all summarized in these tables.
all summarized in these tables. Everything that ended in -1
to name the acid, the name is changed. The pure -1 is changed to -ic.
The pure -1 is changed to -ic. For example, anything that had chloride,
For example, anything that had chloride, if it forms an acid, then with
if it forms an acid, then with chloride, when it forms an acid, it becomes
chloride, when it forms an acid, it becomes hydrochloric acid, as
hydrochloric acid, as indicated here with the formula. And everything with
indicated here with the formula. And everything with sulfide becomes hydrogen sulfide.
sulfide becomes hydrogen sulfide. If it's pure water vapor,
what happens with us? The prefix...
The prefix... no, it doesn't change. The prefix doesn't
no, it doesn't change. The prefix doesn't matter, it stays the same. What
matter, it stays the same. What changes is the ending. So,
changes is the ending. So, everything that ended in -ate is
everything that ended in -ate is changed to -ic, and everything that... It
changed to -ic, and everything that... It ends in "hitos" and changes to "oso." You
ends in "hitos" and changes to "oso." You have to learn those three
have to learn those three things: pure, past, hydrochloric acid, and
things: pure, past, hydrochloric acid, and past "hitos." It
past "hitos." It seems like a game, but that's how it is. So,
seems like a game, but that's how it is. So, for example, an acid that has
for example, an acid that has the bond "para-chlorate," that is, when
the bond "para-chlorate," that is, when perchlorate forms an acid, it forms
perchlorate forms an acid, it forms perchloric acid. That is, I keep everything
perchloric acid. That is, I keep everything except the ending. I change "para-chlorate" to "
except the ending. I change "para-chlorate" to "
the chlorate, the same thing, forwards, nothing happens. At the end, I change "-ate" to "pico" again, just like it was with the logical part. And with the two that end in "hito-" or "a-torric acid," the hypochlorite becomes " has been clear" or "hypo-chlorite."
has been clear" or "hypo-chlorite." And here, I'm actually summarizing that in
And here, I'm actually summarizing that in this little drawing so that it says what needs to be
this little drawing so that it says what needs to be changed.
changed. Tell me, "t bond
today, exercise," I think this is what we do
in practice, or not in practical class, and you usually do it in the
class, and you usually do it in the self-assessment ones, and also the "us" ones, which
self-assessment ones, and also the "us" ones, which are like the additional ones. And also, you
are like the additional ones. And also, you grab any chemistry book,
grab any chemistry book,
which there are seven million of, that's why I'm telling you if... They start doing
start doing exercises, they get overwhelmed
exercises, they get overwhelmed with terminology,
with terminology, but well, it takes practice, that's for sure. And
but well, it takes practice, that's for sure. And Micaela,
Micaela, if I wanted to ask, those exercises
if I wanted to ask, those exercises were already on the page where we have
were already on the page where we have all the information, and the table
all the information, and the table for next week's practical. And Maite can
for next week's practical. And Maite can
correct me if I'm not mistaken, the exercises will be posted
mistaken, the exercises will be posted every Thursday for the
every Thursday for the following week, Wednesday,
following week, Wednesday, Wednesday, Wednesday, pokey. So,
Wednesday, Wednesday, pokey. So, starting tomorrow, you'll have the material
starting tomorrow, you'll have the material for next week. That
for next week. That is, each week we'll be posting them on
is, each week we'll be posting them on Wednesdays, and at the
Wednesdays, and at the end of each week,
end of each week, the solutions will be posted, with the
the solutions will be posted, with the answers from the superstitious ones.
answers from the superstitious ones. The idea is that, for example, when you
The idea is that, for example, when you go to the practicals, you already have
go to the practicals, you already have something prepared regarding the
something prepared regarding the application processes, because that makes
application processes, because that makes the class more dynamic. Otherwise, it's
the class more dynamic. Otherwise, it's basically one of us doing it
basically one of us doing it on the board and you
on the board and you looking there. So, take
looking there. So, take the little things...
the little things... I'm going to stop sharing because my
I'm going to stop sharing because my presentation is finished.
So I can see... I don't see some faces here, luckily. Thank you. And I see the list of
some faces here, luckily. Thank you. And I see the list of participants, and the one who's...
participants, and the one who's... Alexander, go ahead, I just
Alexander, go ahead, I just have to ask about that thing you mentioned regarding the
have to ask about that thing you mentioned regarding the book of books I recommend. If
book of books I recommend. If they're on the website, well, actually,
they're on the website, well, actually, you're going to have some material
you're going to have some material prepared by us to help you with
prepared by us to help you with the topics starting
the topics starting next week. To study this, I'd
next week. To study this, I'd say any general chemistry book. I
say any general chemistry book. I mentioned Brawn and Chance
mentioned Brawn and Chance because they're generally the ones
because they're generally the ones used at the Élysée Institute, but
used at the Élysée Institute, but any general chemistry book has
any general chemistry book has a section on nomenclature and
a section on nomenclature and formulations that will be useful. -
formulations that will be useful. -
There's a question about the practicals this week.
the practicals this week. Next week we'll see what we're going to do. We'll just do
Next week we'll see what we're going to do. We'll just do exercises,
exercises, which means we won't be
which means we won't be using the lab. You do
using the lab. You do n't have a
n't have a lab this semester because
lab this semester because now you're going to have to take
now you're going to have to take this course called Safety,
this course called Safety, Risk Prevention, etc., and only
Risk Prevention, etc., and only when you pass that subject can you move on
when you pass that subject can you move on to the labs. The first lab
to the labs. The first lab for you will be in General Chemistry
for you will be in General Chemistry 2, the Senate of Goods, Administration
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