DP Chemistry (last assessment 2024)

Question 18M.2.hl.TZ2.d

[Maximum mark: 2]

18M.2.hl.TZ2.d

A mixture of 1.00 mol SO₂(g), 2.00 mol O₂(g) and 1.00 mol SO₃(g) is placed in a 1.00 dm³ container and allowed to reach equilibrium.

2SO₂(g) + O₂(g) $\rightleftharpoons$ 2SO₃(g)

The rate constant for a reaction doubles when the temperature is increased from 25.0 °C to 35 °C.

Calculate the activation energy, E_a, in kJ mol⁻¹ for the reaction using section 1 and 2 of the data booklet.

[2]

Markscheme

« $\ln \frac{{{k_1}}}{{{k_2}}} = \frac{{{E_a}}}{R}\left( {\frac{1}{{{T_2}}} - \frac{1}{{{T_1}}}} \right)$ »

T₂ = «273 + 35 =» 308 K AND T₁ = «273 + 25 =» 298 K

E_a = 52.9 «kJ mol^–1»

Award [2] for correct final answer.

[2 marks]

Syllabus sections