Unit 2 N5 Revision

Question 1

steps for naming branched chain alkanes

Answer 1

1. find the longest chain of carbon atoms
2. number from side closest to branch
3. identify branch

Question 2

isomer definition

Answer 2

molecules with the same molecular formula but different structural formula.

Question 3

questions to ask yourself when deciding if molecules are isomers or not

Answer 3

• Is the molecular formula the same?

- Do the molecules have the same name?

Question 4

Halogenation

Answer 4

addition of halogen gp 7
yellow/brown –> colourless
Br-Br bond breaks during reaction and is decolourised
forms a dihaloalkane

Question 5

Hydrogenation

Answer 5

addition of hydrogen

alkene –> alkane

Question 6

Hydration

Answer 6

addition of water

alkene –> alcohol

Question 7

functional group definition

Answer 7

part of molecule which differs from alkane

Question 8

functional group of alcohol

Answer 8

hydroxyl (OH)

Question 9

alcohol general formula

Answer 9

CnH2n+2O or CnH2n+1OH

Question 10

carboxylic acid functional group

Answer 10

carboxyl

Question 11

carboxylic acid general formula

Answer 11

CnH2n+1COOH

Question 12

reactions of carboxylic acids

Answer 12

carboxylic acids are weak acids because they only partially ionise when added to water

Question 13

bases

Answer 13

metal oxide
metal hydroxide
metal carbonate

Question 14

carboxylic acids reactions with bases

Answer 14

react with bases to form a salt
neutralisation reaction
acid + base –> salt + water (+carbon dioxide)

Question 15

uses of salts

Answer 15

preservatives in the food industry

Question 16

naming salts

Answer 16

metal part of the base name plus the carboxylic acid name but change ending from ‘oic’ to ‘oate’
eg methanoic acid + sodium hydroxide –> sodium methanoate

Question 17

what is a physical property?

Answer 17

something that can be observed and measured.

eg melting point