Organics

Question 1

Alkanes general formula

Answer 1

CNH2N (+2)

Question 2

What 3 things do homologous series have

Answer 2

1. Similar trends in chemical reactions
2. Trends in physical properties
3. The same general formulae

Question 3

What is an isomer

Answer 3

Molecules with the same molecular formula but different structural formulae

Question 4

Equation for complete combustion of alkanes

Answer 4

Alkanes+oxygen—> carbon dioxide + water

Question 5

When does incomplete combustion of alkanes occur

Answer 5

Not enough oxygen is present

Question 6

Products of incomplete combustion

Answer 6

Carbon monoxide and soot

Question 7

3 Pollutants of combustion of alkanes

Answer 7

CARBON DIOXIDE
NITROGEN OXIDES
SULPHUR DIOXIDE

Question 8

What happens to nitrous oxides when dissolved in rainwater

Answer 8

Forms acid rain - harmful to enviroment

Question 9

Two details about Alkanes reacting with halogens

Answer 9

It is a substitution reaction because the H swaps the (Br)

It requires UV light because the alkane is pretty unreactive

Question 10

Describe Cracking

Answer 10

Crude oil tends to contain more longer alkanes than shorter ones
The shorter ones are more useful
Cracking breaks down longer alkanes into smaller more useful ones

Question 11

Conditions needed for cracking

Answer 11

Temperature 650*C

Catalyst: Aluminium oxide (Al2O3)

Question 12

Cracking products

Answer 12

Long AlkAne —> Shorter AlkAne + AlkEne

Question 13

Alkenes general formula and feature

Answer 13

CnH2n

C=C double bond

Question 14

What is Saturation

Answer 14

Not having a C=C double bond

AlkEnes are unsaturated because they have a C=C double bond

AlkAnes are saturated because they don’t have a C=C double bond

Question 15

How do Alkenes react with bromine and give 4 details

Answer 15

By breaking the C=C and adding in bromine atoms

• addition reaction because you’re adding the bromine atoms into the alkene
• reaction works without UV light because Alkenes are more reactive than Alkanes
• it works with pure bromine liquid or bromine water (orange)
• the mixture turns orange to colourless because the bromine is used up in the reaction

Question 16

3 points about addition polymers

Answer 16

1. An addition polymer forms when molecules with a C=C add into chains
2. The small molecules that add together are called monomers
3. The long chain they form when added together is called a polymer

Question 17

Composition of crude oil

Answer 17

Mixture of hydrocarbons ( compounds of hydrogen and carbon only )

Question 18

Fractions of crude oil…

Answer 18

Each fraction of crude oil is a mixture of similar hydrocarbons with similar boiling points

As the boiling point increases, the fractions get darker and more viscous

Question 19

How does fractional distillation work

Answer 19

1. Heated crude oil vapours enter the column
2. Vapours ruse until they reach their boiling point where they condense
3. Different vapours condense at different heights due to their different boiling points
4. Similar vapours condense together as a fraction

(Fractions are mixtures containing the hydrocarbons that boil in a particular range)

Question 20

Fractions from cold to hot

Answer 20

Refinery gases
Gasoline
Kerosene
Diesel
Fuel oil
Bitumen