Topic C7 - Organic Chemistry

Question 1

Crude Oil

Answer 1

• Finite Resource
• Mixture of many hyrdrocarbons
• Found in rocks and formed from dead plants
• fossils in mud

Question 2

What are hydrocarbons?

Answer 2

Only contain hydrogen and carbon atoms

e. g
- methane
- ethane
- propane
- butane

Question 3

What is crude oil used for?

Answer 3

- fuel
stock chemicals for:
- polymers
- solvents 
- detergents
- lubricants

Question 4

Complete combustion

Answer 4

An oxidation reaction that occurs when a fuel reacts with plenty of oxygen

Question 5

What does hydrocarbon + oxygen produce?

Answer 5

Carbon dioxide + water

Question 6

Why are hydrocarbons used as fuels?

Answer 6

Because combustion releases a lot of energy

Question 7

As the length of the hydrocarbon chain increases, the…?

Answer 7

1) Boiling point increases
2) Viscosity Increases
3) Flammability decreases

Question 8

Fractional Distillation

Answer 8

A process used to seperate the hydrocarbons in crude oil into fractions according to their boiling points.

Question 9

What happens to shorter hydrocarbons during FRACTIONAL DISTILLATION?

Answer 9

They have lower boiling point, so condense near the top of the column

E.g petrol

Question 10

What happens to longer hydrocarbons during FRACTIONAL DISTILLATION?

Answer 10

Have higher boiling points so condense near the bottom of the column.

Question 11

What are alkanes?

Answer 11

• Contain only single covalent bonds (they’re saturated).
• The simplest type of hydrocarbon
• Most hydrocarbons in crude oil are alkanes

Question 12

What is the formula for the homologous series of alkanes?

Answer 12

CnH2n+2

Question 13

How many carbon atoms in methane?

Answer 13

1

Question 14

How many carbon atoms in ethane?

Answer 14

2

Question 15

How many carbon atoms in propane?

Answer 15

3

Question 16

How many carbon atoms in butane?

Answer 16

4

Question 17

Methane Formula

Answer 17

CH₄

Question 18

Ethane Formula

Answer 18

C₂H₆

Question 19

Propane Formula

Answer 19

C₃H₈

Question 20

Butane Formula

Answer 20

C₄H₁₀

Question 21

What does CRACKING do?

Answer 21

Breaks down long-chain hydrocarbons into shorter, more useful ones.

Question 22

What are alkenes useful for?

Answer 22

• Used to make polymers

- Starting material for making other chemicals

Question 23

Cracking chemical equation

Answer 23

long chain alkane ->

shorter-chain alkane + alkene

Question 24

How are long-chain hydrocarbons vaporised

Answer 24

Long-chain hydrocarbons vaporised by heating.

Question 25

2 methods of CRACKING

Answer 25

1) Catalytic Cracking

2) Steam Cracking

Question 26

How does CATALYTIC CRACKING work?

Answer 26

Hypercarbon vapour is passed over a hot powdered aluminium catalyst.

Question 27

How does STEAM CRACKING work?

Answer 27

Hydrocarbon vapour is mixed with steam and heated to a very high temperature.

Question 28

Alkenes are more reactive than alkanes, TRUE or FALSE?

Answer 28

TRUE

Question 29

What does adding alkene to bromine water do?

Answer 29

Bromine + alkene water = colourless

Adding an alkene to bromine water causes it to change from orange to colourless.