Crude Oil and Fuels

Question 1

Hydrocarbon

Answer 1

A compounds of hydrogen and carbon only

Question 2

Fractional distillation of crude oil

Answer 2

• Crude oil is transported into the fractionating column and heated into vapours (350˚C)
• The vapours evaporate and move up the column.
• The vapours of different hydrocarbons then condense at different points in the column according to their boiling points, with those with high boiling points at the bottom and those with low boiling points at the top.

Question 3

Main fractions obtained from crude oil in order

Answer 3

Refinery gases
Gasoline
Kerosene
Diesel
Fuel oil
Bitumen

Question 4

Uses for refinery gases

Answer 4

• domestic heating
• cooking

Question 5

Uses for gasoline/petrol

Answer 5

fuel for cars

Question 6

Uses for kerosene

Answer 6

fuel for aircraft

Question 7

Uses for diesel

Answer 7

• fuel for some cars
• fuel for trains

Question 8

Uses for fuel oil

Answer 8

• fuel for ships
• fuel for power stations

Question 9

Uses for bitumen

Answer 9

• surface roads
• roofs

Question 10

Trend in colour, boiling point and viscosity of the main fractions

Answer 10

• The boiling point increases as the number of carbon atoms (chain length) increases
• The viscosity increases as chain length increases
• The greater the chain length, the darker in colour the fraction is

Question 11

Sulfur dioxide and nitrogen oxides formation

Answer 11

• combustion of some impurities in hydrocarbon fuels results in the formation of sulfur dioxide
• in car engines, the temperature reached is high enough to allow nitrogen and oxygen from the air to react, forming oxides of nitrogen

Question 12

Acid rain formation + impacts

Answer 12

• Acid rain results when sulfur dioxide (SO2) and nitrogen oxides (NOX) are emitted into the atmosphere and transported by wind and air currents
• The SO2 and NOX react with water, oxygen and other chemicals to form sulfuric and nitric acids.
• This kills trees and fish in lakes
• Acid rain also corrodes limestone buildings and marble statues since these are both made of calcium carbonate (CaCO₃)
• Some metals such as iron are also attacked by acid rain.