Fuels

Question 1

What are crude oils? Describe 4

Answer 1

(i) a complex mixture of hydrocarbons
(ii) containing molecules in which carbon atoms are in chains or rings (names, formulae, and structures of specific ring molecules not required)
(iii) an important source of useful substances (fuels and feedstock for the petrochemical industry)

(IV) a finite resource

Question 2

What do hydrocarbons contain

Answer 2

Carbon and Hydrogen ONLY. Hydrocarbon is compounds

Question 3

What are the 6 different fractions with names and uses

Answer 3

Gases - Used in domestic heating and cooking
Petrol - used as fuel for cars
Kerosene - used as fuel for aircraft
Diesel oil - Used for fuel for some cars and trains
Fuel oil - Used as fuel for large ships and in some power stations
Bitumen - Used to surface roads and roofs.

Question 4

Explain why Cracking is Necessary

Answer 4

It helps to match the supply of fractions with the demand for them

Since cracking converts larger hydrocarbons into smaller hydrocarbons, the supply of fuels is improved. This helps to match supply with demand.

Question 5

State the products, other than water and carbon dioxide, that can form during incomplete combustion

Answer 5

Carbon monoxide and Carbon

Question 6

Name one pollutant that can lead to acid rain

Answer 6

Nitrogen Oxide a mix with water in clouds to form dilute nitric acid, this then falls as acid rain

Question 7

Two advantages of using hydrogen as a fuel in cars rather than petrol

Answer 7

The reaction between oxygen and hydrogen is less polluting

Water is a renewable resource and is widely available

Question 8

Define the term cracking

Answer 8

Cracking turns long saturated molecules into smaller unsaturated and alkene molecues

Question 9

Name two types of hydrocarbons that are produced as a result of cracking

Answer 9

Octane, Decane