Air quality and climate — GCSE Chemistry practice questions

Question 1

Fig. 1 shows the composition of clean, dry air by volume.

Which row identifies gas X and gas Y?

Accepted Answer

A: nitrogen · oxygen. Clean, dry air is about 78 % nitrogen (X) and 21 % oxygen (Y); the remaining 1 % is mainly argon with a little carbon dioxide.

Question 2

A country wants to reduce the acid rain caused by its coal-fired power stations.

Which action would help?

Accepted Answer

B: burning coal that contains less sulfur. Sulfur dioxide, formed when sulfur compounds in coal burn, causes acid rain, so burning low-sulfur coal reduces it. Trees and fewer cattle help against climate change, and soot filters remove particulates, not acidic gases.

Question 3

A city council lists four plans to lower the amount of greenhouse gases in the atmosphere.

Which plan would **not** help?

Accepted Answer

D: fitting catalytic converters to all council vans. Catalytic converters change carbon monoxide into carbon dioxide and nitrogen oxides into nitrogen; they do not remove carbon dioxide, a greenhouse gas. Trees take in carbon dioxide, fewer cattle release less methane, and wind turbines replace burning coal.

	gas X	gas Y
A	nitrogen	oxygen
B	oxygen	nitrogen
C	nitrogen	carbon dioxide
D	oxygen	argon