C14 Crude Oil And Fuels

Question 1

Name the process where hydrocarbon fractions are separated

Answer 1

Fractional distillation

Question 2

Explain and describe the process of fractional distillation

Answer 2

• The fractions are vaporised
• Hydrocarbon gasses enter the separation column
• The hydrocarbon gasses will rise up the separation column
• As they rise up the column they cool down
• When different fractions reach their boiling point in the column they condense
• Because long chains have a higher boiling point they cool and become a liquid faster and smaller chains are extracted as a gas

Question 3

3 characteristics of long chain hydrocarbons

Answer 3

• Low flammability
• High boiling point
• High viscosity (thick)

Question 4

3 characteristics of short chain hydrocarbons

Answer 4

• high flammability
• low boiling point
• low viscosity (runny)

Question 5

Name the first 10 alkanes

Answer 5

Methane, Ethane, Propane, Butane, Pentane, Hexane, Heptane, Octane, Nonane, Decane

Question 6

Name the first 4 alkenes

Answer 6

Ethene, propene, butene, pentene

Question 7

What type of fractions are collected from the top of a separation column in fractional distillation

Answer 7

Short chains:
- Petroleum
- cooking gas

Question 8

What type of fractions are collected from the bottom of a separation column in fractional distillation

Answer 8

Long chains (known as residue):
- Long chains used in making roads

Question 9

What type of fractions are collected from the middle of a separation column in fractional distillation

Answer 9

Medium sized chains:
- Kerosene (plane fuels)

Question 10

Difference (in structure) between alkanes and alkenes

Answer 10

Alkenes contain double bonds between 1 set of carbon atoms

Question 11

How do you tell the difference between an alkane and an alkene

Answer 11

• Mix with bromine water:
  - If alkane nothing will happen
  - If alkene the bromine water will turn from orange to colourless

Question 12

Name the 2 processes used to turn an alkane into an alkene (cracking)

Answer 12

• Catalytic cracking
• Steam cracking

Question 13

Describe the steps of catalytic cracking

Answer 13

• Vaporise hydrocarbon (heat to 550 degrees celsius)
• pass them over a hot catalyst (Aluminium oxide)

Question 14

Describe the steps of steam cracking

Answer 14

• Mix the hydrocarbon with steam at 800 degrees celsius

Question 15

What is crude oil?

Answer 15

A mixture of different length chains of hydrocarbons formed millions of years ago from dead biomass. This material is non-renewable