CAIE A-Level Chemistry AS 12.1.5 Role of No and No2 in the Formation of Acid Questions

Practise equations for direct nitric-acid formation and the catalytic role of NO and NO2 in oxidising atmospheric SO2.

Syllabus
2028–2030
Course
Chemistry 9701
Level
AS

Exam points

  • Write or interpret the direct NO₂ + H₂O (and O₂ where required) pathway forming nitric acid, a component of acid rain.
  • Explain the NO₂-catalysed oxidation of atmospheric SO₂ to SO₃ using NO₂ + SO₂ → NO + SO₃ and NO + ½O₂ → NO₂.
  • Complete the acid-rain pathway by relating SO₃ reacting with atmospheric water to H₂SO₄ and identifying NO₂ as regenerated catalyst.

CAIE A-Level Chemistry AS 12.1.5 Role of No and No2 in the Formation of Acid Questions question 1

[Maximum number: 1]

Nitrogen dioxide is a gas that contributes to air pollution. It is produced in internal combustion engines.

Which statement is correct?

A

Nitrogen dioxide acts as a catalyst in the atmospheric oxidation of sulfur dioxide to sulfur trioxide.

B

Nitrogen dioxide reacts to form nitrogen monoxide in the catalytic converter of a car exhaust system.

C

PAN forms when nitrogen dioxide reacts with the gases formed by complete combustion of the fuel.

D

Under high pressure in an internal combustion engine, nitrogen dioxide forms from impurities in the fuel.

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