Chemistry 9701 · AS & A Level · Nitrogen and sulfur

Nitrogen and sulfur — practice question

Nitrogen accounts for roughly $79\%$ of the Earth’s atmosphere. Because it is a constituent element of proteins, it is found in living organisms. Atmospheric nitrogen is used in the Haber process to make ammonia.
(a)[1]

Write an equation for how ammonia is formed in the Haber process.

(b)[4]

The Haber process is normally run at a high pressure ranging from $60$ to $200$ atmospheres (from $60 \times 10^5\,\text{Pa}$ to $200 \times 10^5\,\text{Pa}$). State two other key operating conditions used in the Haber process. For each one, explain why it is chosen.

(c)[1]

State one large-scale use of ammonia, other than in the manufacture of nitrogenous fertilisers.

(d)[2]

The careless use of nitrogenous fertilisers can harm lakes and streams. This is called eutrophication. What processes happen when excessive quantities of nitrogenous fertilisers enter lakes and streams?

(e(i))[2]

Outline how each of these pollutants may be formed in an internal combustion engine. CO NO

(e(ii))[4]

State the main hazard linked to each of these pollutants. CO NO

(f(i))[1]

Which metal is most often used as the catalyst in a catalytic converter?

(f(ii))[2]

Construct one balanced equation showing how a catalytic converter removes both CO and NO from exhaust gases.

Worked solution & mark scheme

This 17-mark question has a full step-by-step worked solution and mark scheme. One marking point: $N_2 + 3H_2 \rightleftharpoons 2NH_3$

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