May/June 2026 Paper 23

2026 · 5 questions · 32 parts · 60 marks

0/60 marks

0Correct0Partial0Wrong32Unattempted

Filters0 active

Questions

Select a part to jump to its question

Finish set

1(a)(i)1(a)(ii)1(b)(i)1(b)(ii)1(c)(i)1(c)(ii)1(d)

–/12 mks

2(a)2(b)2(c)

–/9 mks

3(a)3(b)3(c)3(d)(i)3(d)(ii)

–/13 mks

4(a)(i)4(a)(ii)4(a)(iii)4(b)(i)4(b)(ii)4(c)(i)4(c)(ii)4(c)(iii)4(d)(i)4(d)(ii)

–/14 mks

5(a)(i)5(a)(ii)5(b)(i)5(b)(ii)5(b)(iii)5(c)(i)5(c)(ii)

–/12 mks

3(a)Enthalpy Changes Energy Profiles CalorimetryMedium2 marks

The conditions used for the conversion of sulfur dioxide to sulfur trioxide in the Contact process are carefully controlled.

reaction 1 2 S O_{2} (g) + O_{2} (g) ⇌ 2 S O_{3} (g) Δ H = - 196 kJ mol^{- 1}

Complete Figure 3.1 to show the reaction pathway diagram for reaction 1. Draw arrows to represent the enthalpy change,

Δ H

, and activation energy,

E_{A}

Draw with the mouse or a finger.

3(b)Dynamic Equilibria Equilibrium ConstantsEasy2 marks

Define Le Chatelier's principle.

Answer

0 words

3(c)Dynamic Equilibria Equilibrium ConstantsHard3 marks

In industry, reaction 1 occurs at

400 - 450^{\circ} C

and

110 - 200 kPa

with a catalyst.

Complete Table 3.1 by using the terms 'increase', 'decrease' or 'no change' for each condition.

effect on value of equilibrium constant,

K_{p}

effect on yield of product at equilibrium

effect on rate of reaction

3(d)(i)Dynamic Equilibria Equilibrium ConstantsMedium3 marks

A sealed tube that initially contains only

2.00 mol

S O_{2} (g)

and

2.00 mol

O_{2} (g)

is left to reach equilibrium.

At equilibrium,

1.96 mol

S O_{3} (g)

is present and the total pressure is

150 kPa

reaction 1 2 S O_{2} (g) + O_{2} (g) ⇌ 2 S O_{3} (g)

Complete Table 3.2.

Table 3.2

	$S O_{2} (g)$	$O_{2} (g)$	$S O_{3} (g)$
amount initially / mol	2.00	2.00	0
amount at equilibrium / mol			1.96
mole fraction at equilibrium	0.01325	0.3377

Row	Response
amount of $S O_{2} (g)$ at equilibrium / mol	Table answer so2eq_Response
amount of $O_{2} (g)$ at equilibrium / mol	Table answer o2eq_Response
mole fraction of $S O_{3} (g)$ at equilibrium	Table answer so3mf_Response

3(d)(ii)Dynamic Equilibria Equilibrium ConstantsHard3 marks

Table 3.3 shows the mole fractions at equilibrium of

S O_{2} (g)

O_{2} (g)

and

S O_{3} (g)

under different conditions.

Table 3.3

	$S O_{2} (g)$	$O_{2} (g)$	$S O_{3} (g)$
mole fraction at equilibrium	0.360	0.019	0.621

Calculate

K_{p}

200 kPa

using the data from Table 3.3. Include units in your answer.

Working,

K_{p}

value and units

0 words