0:02 this is M sjcam in this video I'll be
0:04 looking at the addition reactions of the
0:08 alkanes alkenes are reactive molecules
0:09 due to the presence of a carbon to
0:12 carbon double bond also known as an
0:15 alkyl group they undergo electrophilic
0:17 addition reactions in which two
0:20 molecules combine to produce a larger
0:22 molecule here we have examples of
0:25 symmetrical alkenes we have ethene on
0:28 the Left Butte to een in the middle and
0:32 on the right we have hex 3 in as we can
0:33 see each molecule has a carbon two
0:36 carbon double bond which is the reactive
0:38 part of the molecule when alkenes
0:40 undergo addition reactions the carbon
0:43 the carbon double bond opens up creating
0:46 additional bonding positions we look at
0:48 the difference between symmetrical and
0:51 unsymmetrical alkenes at the end of the
0:53 video the first type of addition
0:56 reaction we look at is hydrogenation in
0:59 this reaction an alkene reacts with
1:03 hydrogen to form an alkane so here we
1:06 can see c2 h4 which is ethene reacting
1:10 with hydrogen to form c2h6 which is
1:13 ethane in the reaction the carbon to
1:15 carbon double bond opens up and we add
1:18 two hydrogen atoms to the molecule note
1:20 that this reaction is usually carried
1:24 out using a nickel catalyst and here we
1:26 can see the overall chemical equation
1:29 for the reaction the next type of
1:32 reaction is halogenation in halogenation
1:35 alkenes react with halogens to produce
1:38 dye halogen o compounds so here we have
1:41 ethene reacting with bromine to produce
1:45 one to die bromo ethane and here we have
1:48 the chemical equation for the reaction
1:51 alkenes also react with hydrogen halides
1:56 that's HCl HBR Ohi to produce halogen no
1:59 alkanes so here we have the reaction of
2:02 ethene with hydrogen bromide to produce
2:05 bromo ethane and once again here we have
2:08 the chemical equation for the reaction
2:10 the next type of reaction is hydration
2:13 in which an alkene react
2:16 with steam to form an alcohol so in this
2:19 reaction we have ethene reacting with
2:21 water in the form of steam in the
2:24 presence of a sulfuric acid catalyst to
2:26 form ethanol and here we have the
2:30 equation for the reaction and finally we
2:31 look at the difference between the
2:33 reactions of symmetrical and
2:36 unsymmetrical alkenes the addition
2:39 reactions of symmetrical alkenes produce
2:42 only one possible product so here we
2:44 have Butte Queen which is a symmetrical
2:48 alkene reacting with hydrogen chloride
2:50 the only possible product of the
2:53 reaction is to chloro butane next we
2:56 have the reaction of Butte one in which
2:59 is an unsymmetrical alkene when Butte
3:00 one in react with hydrogen chloride
3:04 there are two possible products they are
3:09 one chloro butane and 2-chloro butane to
3:11 predict a major product of the reaction
3:14 we apply markovnikov's rule which is
3:16 only covered in the higher level
3:19 syllabus for high level students in this
3:21 case the major product will be 2-chloro
3:24 butane this is due to the stability of
