MODULE 4

Question 1

Types of formula

Answer 1

General -> homologou sseries
Structural -> minimul detail e.g. CH3CH2CH3
Displayed -> all the bonds
Skeletal -> don’t show C or H

Question 2

Rules for naming

Answer 2

• Longest C chain first and then branches
• Identify functional groups
• Highest priority group has the lowest number
• Put groups in alphabetical order

Question 3

Suffixes in order

Answer 3

Esters idk - double bon and single O, butyl butanoate

2. Aldehydes - butanal
3. Ketones - butan-2-one
4. Alcohols - butan-2-ol
5. Alkenes
6. Haloalkanes

Question 4

Structural isomerism

Answer 4

Same molecular formula but different structure
- Chain - carbon chain
- Positional - placement of functional group
- Functional group - tupe of group e.g. aldehydes and ketones

Question 5

Properties of alkanes

Answer 5

• Sigma bonds have free rotation
• Tetrahedral arrangement 109.5
• Straight chains have more contact points = stronger LDF

Question 6

Combustion of alkanes

Answer 6

Incomplete produces CO and C

Causes pollutants such as SO2 and NOx which cause acid rain, SO2 is neutralised by CaO

Catalytic converters reduce pollution
- 2CO + 2NO -> N2 + 2CO

Question 7

Properties of alkenes

Answer 7

Carbones in the double bond have a panar arrangement
Carbones without double bond have a tetrahedral arrangement
- Double bonds have high elecron density

Question 8

How do isomers differ

Answer 8

In polarity. E is summertrical so is non polar while Z is polar

Question 9

Biodegradable polymers

Answer 9

Polyesters are made by condensation reactions so can be broken by hydrolysis.

Polyalkenes are not biodegradable and must be disposed of - Recycling, landfil, used as fuel

Question 10

Properties of alcohols

Answer 10

Tetrahedral geometry around carbons, bent geometry around OH due to lone pairs

Dipoles - low boiling points, use as solvents

Question 11

Oxidation of alchohols

Answer 11

Primary alchols + [O] + gentle heat -> aldehydes
Aldehydes + [O] + vigourous heat & reflux -> carboxylic acids

Secondary alcohols + [O] -> ketones

Tertiary alchohols cannot be oxidised.

Question 12

Trend in hydrolysis of primary alkanes

Answer 12

• Test for halide ions
• Rate at which precipitate forms indicates the strength
• Iodoalkanes react the fastest and therefore have the weakest bond

Question 13

Depletion of ozone

Answer 13

CFCs used as solvents and for refrigeration

CF2Cl2 -? Cf2Cl. Cl.

Cl. + O3 -> ClO. + O2
ClO. + O3 -> ClO. + O2
2Cl. -> Cl2

Overall = 2O3 -> 3O2