0:03 welcome to the first video for chapter 4
0:05 section 3 chemical nomenclature
0:07 in this first video i'll be focusing on
0:09 ionic compounds and the second
0:11 video will be focused on molecular compounds
0:12 compounds
0:14 the learning objective for this video is
0:16 to derive names for common types of
0:18 inorganic compounds using a systematic
0:20 approach we will not be covering
0:23 organic compounds which are compounds
0:24 that are
0:27 mostly consist of carbons and hydrogens
0:29 we will be looking at that at a
0:31 different time
0:32 so the first thing is to think about
0:39 and essentially it's a collection of
0:41 rules for naming things
0:43 it's important to us because when we're
0:44 looking at chemicals
0:47 we often identify them by their formula
0:49 but we also need to identify
0:52 compounds by their name which means that
0:53 names must be unique
0:57 and they must be recognizable
0:59 so we need to have a system for that and
1:00 that's what this video is going to be about
1:02 about
1:03 so as i said we're going to focus on
1:05 ionic compounds to begin
1:06 and there are several different
1:08 categories of ionic compounds and we
1:10 will just move through them one by one
1:12 and talk about the process
1:14 for naming each kind the first and
1:15 simplest kind of
1:17 ionic compound that we're going to see
1:20 are ones that contain only monatomic
1:23 ions that is to say they the ions
1:25 consist of only one
1:28 atom and the process for naming these
1:30 is quite simple first you name the
1:31 cation and the
1:33 and then second you name the anion but
1:36 you change the ending of that
1:39 name to ide so for example here
1:41 we've got sodium chloride and i will
1:43 break that name down for you
1:46 we have this first guy is the cation
1:51 and then the second element we're going
1:54 to put second it's the anion
1:57 and it's chlorine but we change
2:01 in to ide so chloride
2:05 this next one consists of calcium and sulfur
2:06 sulfur
2:14 solidified
2:16 and then this last one uh even though
2:18 we've got these ratios right we have
2:19 these numbers
2:21 involved here as uh we're looking at the
2:23 formula of of this compound
2:24 but it turns out that for ionic
2:27 compounds um the ratio is determined by
2:28 the charge of the ions
2:38 oxide because we know
2:41 that oxygen makes a two minus
2:43 ion and aluminum makes a three plus ion
2:45 and that is the one ratio that they can
2:46 combine in
2:49 so monatomic ions are quite simple to name
2:51 name
2:57 ionic compound that we're going to be
2:58 naming are ones that contain
3:00 polyatomic ions these are a little bit
3:02 more complicated because you have to recognize
3:03 recognize
3:05 that there's a polyatomic ion and then
3:06 you need to know
3:08 the name of the polyatomic ion so i'm
3:11 going to list some polyatomic ions that
3:12 you should memorize
3:16 so on this side of the table we've got
3:18 the negatively charged the anions and
3:20 over here we've got the positively
3:20 charged the
3:23 cation so i'll start off with this guy ammonium
3:24 ammonium
3:27 that is nh4 plus and it's the only
3:28 cation that we're going to be dealing with
3:29 with
3:30 uh all right so then we'll go through
3:32 the anions so nitrate
3:36 is no3 minus chlorate
3:39 clo3 minus carbonate
3:43 c o three two minus sulfate
3:47 so4 2 minus phosphate
3:50 po4 3 minus and then we have hydroxide
3:51 which is just
3:54 oh minus and then we have acetate and
3:56 acetate is an interesting one
3:57 it can be written a couple of different
4:00 ways so one way to write acetate
4:03 is c2h3o2
4:05 minus or a different way to arrange
4:07 these atoms that kind of more accurately
4:09 represents the structure of the acetate
4:16 o ch3coo minus so those are actually
4:17 they have the same number of each of the
4:18 kinds of elements
4:20 um but it's just two different ways to
4:22 write that ion
4:24 so um yeah so you'll probably need to
4:25 memorize these guys
4:27 or at least become familiar with them
4:28 because you're going to need to recognize
4:29 recognize
4:32 when um compounds contain these things
4:35 uh and and and they'll often be clues um
4:39 about something that's going on so when
4:40 we name
4:42 ionic compounds that contain polyatomic
4:43 ions it's quite similar
4:45 we just name the cation and then we name
4:46 the anion
4:49 um and so this is quite simple here
4:50 we've got
4:53 a polyatomic ion and we notice that it has
4:53 has
4:55 some sodiums in it and then it's got
4:58 this guy and this is our po4
5:00 three minus which we can notice because
5:01 it's uh
5:04 um there's three units of the sodium
5:06 plus ion per one unit of the phosphate
5:09 three minus ion so what this is going to
5:10 give us
5:14 is sodium and then we just name
5:23 same thing we can have koh this is this
5:25 is we're going to recognize that hey oh
5:26 this is our hydroxide
5:28 so we're going to have potassium and
5:30 then we have hydroxide and our name
5:38 is potassium hydroxide
5:40 this works the exact same way if you're
5:42 dealing with ammonium so a really common
5:45 compound that contains ammonium whoops
5:47 um i will erase that
5:50 uh plus charge since that does not exist
5:52 once we put it into its compound
5:55 form so um if we're looking at
5:57 this compound we do the exact same thing
5:58 we name
6:08 and then we name our anion and here we should
6:08 should
6:14 so anytime you're taking an element and
6:16 making it into an anion you need to use
6:17 the ide
6:19 suffix when we're using these anions
6:20 that uh
6:21 that are polyatomic and these are the
6:23 names of them we don't need to change
6:30 the next category is containing a metal
6:32 with a variable charge for example
6:35 iron so what this means is um
6:37 if the compound that you're naming
6:38 contains a metal
6:41 like iron that can have multiple charge
6:43 states for example iron
6:46 can exist as a two plus ion or it can
6:47 also be
6:50 a three plus so we don't know
6:54 um which we've got and so the naming is
6:55 a little bit more complicated
6:57 and essentially it's just a little bit
6:59 uh all we do is we just add a roman
7:01 numeral to denote the charge state
7:05 so here we would name this iron chloride
7:07 and in fact that's still what we name it
7:09 we just add
7:12 a roman numeral in parentheses to denote
7:15 the charge state here we know that
7:16 chloride is a minus one
7:18 we've got two of them so our iron must
7:19 be a plus two
7:21 so we're gonna say this is iron two chloride
7:23 chloride
7:24 a different kind of iron chloride that
7:26 we can have is uh when we've got the
7:29 other charge state of iron
7:30 so again this is going to be iron chloride
7:35 but now it's the other kind of iron chloride
7:36 chloride
7:38 and we know that the chloride ions tend
7:40 to be minus one
7:43 and that means that our iron must be a
7:44 plus three since there are three
7:46 chloride ions here
7:49 so this is going to be iron iii chloride
7:51 um these are different chemicals they
7:52 have different compounds and you use
7:54 them for different things and so it's
7:55 very important to be able
7:57 to tell the difference between these two
7:59 just based on that name
8:02 a note about old nomenclature rules so
8:05 uh back in the day if there were charge
8:06 states multiple
8:08 metals with different charge states um
8:11 there was a notation so it would be
8:20 or ferrous chloride
8:24 and so ferro it comes from the name of the
8:24 the
8:27 of the element um and ich
8:30 is uh the higher charge state so this
8:37 and us is the lower charge state so this
8:39 would have been the iron two
8:43 whoops fe cl2 um so
8:44 you will still see these sometimes and
8:46 so just a note that that's what that
8:47 means it's it's about the charge state
8:48 these are
8:51 both iron chloride compounds but one is the
8:51 the
8:57 all right so the next kind of compound
8:59 that we'll need to be able to name
9:02 are ones that have waters attached
9:04 and we call these hydrates so these look
9:06 like this this is an example where you have
9:07 have
9:09 some kind of chemical compound and then
9:11 you have this dot
9:12 and then some waters and there's usually
9:15 a number of water molecules attached
9:18 what this means is that when you form
9:20 when you when you when this is in its
9:21 crystal form
9:24 each formula unit that's shown here has
9:26 this many formula units of water
9:29 um sort of in the crystal structure so
9:31 if you go and get this out of the jar
9:35 each mole of the stuff that you get out
9:36 you will also get
9:38 this much water and this changes the
9:40 molar mass of the compound and some
9:41 other important things
9:44 so it's really important to know what uh
9:46 hydrate you are dealing with and there
9:48 can be multiple different versions
9:49 multiple different hydrates for
9:51 different compounds so let's go ahead
9:52 and name this one
9:53 so first of all we're going to name our compound
9:55 compound
9:58 cu is copper and this guy is
9:59 unfortunately a multiple charge state
10:01 it's a transition metal
10:03 so we need to figure out what its charge
10:04 is here
10:07 luckily its partner is a polyatomic
10:09 which we know so this is sulfate
10:12 and this is a two minus so therefore uh
10:14 because of the ratio it's a one to one
10:16 ratio between the cation and the anion
10:18 we know that this must be the two plus
10:20 form of copper
10:22 so we're going to go ahead and name this
10:24 as copper sulfate
10:25 but we're going to use our roman numerals
10:32 and then we name the hydrate and what we do
10:33 do
10:36 is use the greek prefix for five so we
10:37 come over here and find our
10:40 um our group greek prefixes so penta is five
10:41 five
10:44 and then we're just going to see penta
10:46 whoops i missed the end penta
10:50 hydrate and that's the name of our hydrate
10:51 hydrate
10:52 so real quick i'm gonna run through the
10:54 rest of the greek prefixes so mono is one
10:54 one
10:58 die is two tri is three tetra is four
11:02 penta is five hexa is six hepta
11:05 is seven octa is nine nana
11:09 whoops octa is eight nana is nine and deca
11:10 deca
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