Air Quality & Climate (Cambridge (CIE) IGCSE Combined Science: Chemistry): Exam Questions

Gasoline (petrol) is a carbon-containing fuel.

Some cars use gasoline as a fuel. The exhaust emissions from these cars contain carbon dioxide, carbon monoxide and carbon particulates.

Describe how each of these three substances forms in a car engine.

(i) Fig. 6.1 represents a molecule of carbon dioxide.

O=C=O

Fig. 6.1

Carbon dioxide contains two double bonds.

Explain why carbon dioxide is not an unsaturated molecule.

[1]

(ii) Increased carbon dioxide in the atmosphere contributes to climate change.

Describe two ways to reduce the rate at which carbon dioxide is released into the atmosphere.

[2]

Carbon monoxide is toxic to living organisms in the environment. A catalytic converter is a device that is used in cars to reduce carbon monoxide emissions.

The symbol equation for one of the reactions in a catalytic converter is shown.

..........CO + ..........NO → ..........CO₂ + N₂

(i) Complete the balanced symbol equation.

[1]

(ii) State one other environmental problem that this reaction helps to reduce.
Explain your answer.
environmental problem .................................................................
explanation .............................................

[2]