4.3 Burning Fuels

Question 1

What happens when pure hydrocarbons are burnt completely?

Answer 1

They are oxidised to carbon dioxide and water

Question 2

Why are the fuels we use not always burnt completely?

Answer 2

Because they may also contain other substances

Question 3

Write a word equation for the complete combustion of ethane.

Answer 3

Ethane + Oxygen —> Carbon Dioxide and Water

Question 4

In a limited supply of air, what may happen?

Answer 4

Incomplete combustion which may produce carbon monoxide

Question 5

What is produced in incomplete combustion?

Answer 5

Carbon monoxide, carbon and some of the hydrocarbons not burnt which produces solid particles that contain soot and unburnt hydrocarbons called particulates

Question 6

What do most fossil fuels contain?

Answer 6

Sulfur compounds

Question 7

What happens when fossil fuels burn?

Answer 7

The sulfur compounds produce sulfur dioxide

Question 8

What does sulfur dioxide cause?

Answer 8

Acid rain

Question 9

At the high temperatures produced when fuels burn, what may happen to oxygen and nitrogen?

Answer 9

They may combine to form nitrogen oxides which also cause acid rain