plumiReversible reactions and equilibrium: Edexcel GCSE Combined Science questions
Every Edexcel GCSE Combined Science exam question on Reversible reactions and equilibrium (specification points 4.13–4.17), 2018–2025, with its mark scheme and examiner’s report.
Paper
All papers
Exam
All years
Calculations
Q6(b)(i)
The whole paper ↗Q6(b)(ii)
The whole paper ↗Q6(b)(iii)
The whole paper ↗Q6(c)
The whole paper ↗Q3(a)(i)
The whole paper ↗Q3(a)(ii)
The whole paper ↗Q3(a)(iii)
The whole paper ↗Q3(a)(iv)
The whole paper ↗Q3(b)
The whole paper ↗Q1(c)(i)
The whole paper ↗Q4(c)
The whole paper ↗Q3(a)
The whole paper ↗Q3(b)
The whole paper ↗Q3(c)
The whole paper ↗Q3(d)(i)
The whole paper ↗Q3(d)(ii)
The whole paper ↗Q5(c)(i)
The whole paper ↗Q4(a)
The whole paper ↗Q4(b)
The whole paper ↗Q5(a)(ii)
The whole paper ↗
All 20 questions on Reversible reactions and equilibrium, as a list
- June 2025, Chemistry Paper 1 Higher, Q6(b)(i) (2 marks): Explain what happens when the reaction reaches dynamic equilibrium. (2)
- June 2025, Chemistry Paper 1 Higher, Q6(b)(ii) (1 mark): Figure 4 shows the changes in percentage yield of ammonia at equilibrium as temperature increases, at a pressure of 300 atmospheres and at a pressure of 1000 at
- June 2025, Chemistry Paper 1 Higher, Q6(b)(iii) (2 marks): In industry, a pressure of 200 atmospheres is used for the Haber process. Using Figure 4, explain what happens to the position of dynamic equilibrium if the pro
- June 2025, Chemistry Paper 1 Higher, Q6(c) (4 marks): Ammonia can also be made by heating ammonium chloride. NH4Cl(s) NH3(g) + HCl(g) A sample of solid ammonium chloride is heated in a boiling tube. After a few min
- June 2023, Chemistry Paper 1 Higher, Q3(a)(i) (3 marks): Write the balanced equation for the reversible reaction between nitrogen and hydrogen to make ammonia, NH3. (3)
- June 2023, Chemistry Paper 1 Higher, Q3(a)(ii) (1 mark): Which row shows the typical conditions of temperature and pressure used in the Haber process? (1) temperature in °C pressure in atmospheres A 250 100 B 250 200
- June 2023, Chemistry Paper 1 Higher, Q3(a)(iii) (1 mark): In the Haber process, iron is added to the vessel where the nitrogen and hydrogen react. State the purpose of the iron. (1)
- June 2023, Chemistry Paper 1 Higher, Q3(a)(iv) (2 marks): The reaction between nitrogen and hydrogen to make ammonia can reach dynamic equilibrium. The reaction gives out heat. Explain how the position of equilibrium c
- June 2023, Chemistry Paper 1 Higher, Q3(b) (3 marks): Compound A is a dark brown gas. Compound B is a colourless gas. Two molecules of A combine to form one molecule of B in a reversible reaction. You are given a s
- November 2021, Chemistry Paper 1 Higher, Q1(c)(i) (3 marks): Complete the balanced equation for this reaction, including the three missing state symbols. (3) ( ) + HClO (aq) ( ) + ( )
- November 2021, Chemistry Paper 1 Higher, Q4(c) (1 mark): When chloride ions are added to a pale blue solution containing copper ions, the mixture turns yellow. This is a reversible reaction. yellow solution + water
- November 2021, Chemistry Paper 1 Foundation, Q3(a) (2 marks): The nitrogen and hydrogen are obtained from raw materials. Draw one straight line from each gas to the raw material it is obtained from. (2) gas raw material ai
- November 2021, Chemistry Paper 1 Foundation, Q3(b) (2 marks): When nitrogen and hydrogen are reacted together, the reaction can reach a dynamic equilibrium. Use words from the box to complete the sentences about dynamic eq
- November 2021, Chemistry Paper 1 Foundation, Q3(c) (2 marks): The reaction between nitrogen and hydrogen happens at a pressure of 200 atmospheres. Another unit of pressure is Pascals, Pa (1 atmosphere = 101 325 Pa). Calcul
- November 2021, Chemistry Paper 1 Foundation, Q3(d)(i) (1 mark): Complete the table showing • the number of hydrogen molecules before reaction • the number of hydrogen molecules at equilibrium • the change in the number of hy
- November 2021, Chemistry Paper 1 Foundation, Q3(d)(ii) (2 marks): Complete the equation for this reaction. (2) 2 NH3 +
- November 2021, Chemistry Paper 1 Foundation, Q5(c)(i) (3 marks): Complete the balanced equation for this reaction, including the three missing state symbols. (3) ( ) + HClO (aq) ( ) + ( )
- June 2019, Chemistry Paper 1 Higher, Q4(a) (4 marks): Hydrated copper sulfate, CuSO4.5H2O, is a blue solid. Anhydrous copper sulfate, CuSO4, is a white solid. Heat energy is needed to convert hydrated copper sulfat
- June 2019, Chemistry Paper 1 Higher, Q4(b) (2 marks): Hydrogen reacts with iodine to form hydrogen iodide. Iodine gas is purple and hydrogen iodide gas is colourless. H2(g) + I2(g) U 2HI(g) Hydrogen and iodine are
- June 2018, Chemistry Paper 1 Higher, Q5(a)(ii) (2 marks): Ammonia, NH3, is made by reacting nitrogen with hydrogen. Write the balanced equation for this reaction. (2)
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