C9 - Crude Oil And Fuels

Question 1

Hydrocarbons

Answer 1

A chain of hydrogen and carbon atoms

Question 2

Alkanes

Answer 2

Saturated hydrocarbons

C(n) H(2n+2)

Question 3

Bonding in alkanes

Answer 3

Held together by covalent bonds

Single carbon bond

Question 4

Alkenes

Answer 4

Unsaturated hydrocarbons

C(n) H(2n)

Question 5

Bonding in alkenes

Answer 5

Held together by covalent bonds

Double covalent bonds

Question 6

Fractional distillation

Answer 6

Crude oil is vaporised and enters the fractioning column

The column is very hot at the bottom but much cooler at the top. As the vaporized oil rises, it cools and condenses.

Heavy fractions have a high boiling point and condense near
the bottom of the column.

Lighter fractions have a lower boiling point and condense further up the column.

Question 7

Complete combustion

Answer 7

When a hydrocarbon burns with a good supply of O2

Products are CO2 and H2O

Question 8

Incomplete combustion

Answer 8

When a hydrocarbon is burned with a bad supply of O2

Products are CO, C, and H2O

Question 9

Test for alkenes

Answer 9

Add orange bromine water to a liquid

If it changes colour from orange to colourless an alkene is present

Question 10

Catalytic cracking

Answer 10

When a catalyst is used to break down the hydrocarbon into an alkane and a alkene

High temperature and pressure are needed

Question 11

Thermal cracking

Answer 11

When high temperatures and pressures are used to break down hydrocarbons into an alkane and alkene

Question 12

Reasons for cracking

Answer 12

Smaller hydrocarbons are in high demand for fuels