Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Physical Chemistry
442 practice questions
Topics covered
Practice questions
371–380 of 442
Question 371
1 mark · Normal
Answer and check →Which statement about ΔH for a reversible reaction is correct?
- A.ΔH always refers to the forward reaction.
- B.ΔH is positive for all exothermic reactions.
- C.ΔH is the same for both directions of the reaction.
- D.ΔH is only given for endothermic reactions.
Question 372
2 marks · Normal
Answer and see the solution →Explain what happens to the position of equilibrium when temperature is increased in a reversible reaction.
Question 373
4 marks · Normal
Answer and see the solution →The equation below shows a reversible reaction.
(a)[1 mark]Is the forward reaction exothermic or endothermic? Explain your answer.
(b)[2 marks]Predict what happens to the position of equilibrium if the temperature is decreased. Explain your answer.
(c)[1 mark]Which direction (left or right) is favoured when temperature is increased? Explain.
Question 374
2 marks · Hard
Answer and see the solution →A reversible reaction is at equilibrium. The forward reaction is exothermic. Explain what happens to the position of equilibrium if the temperature is increased.
Question 375
5 marks · Hard
Answer and see the solution →The following reversible reaction is at equilibrium:
(a)[2 marks]State whether the forward reaction is exothermic or endothermic. Explain how you know.
(b)[3 marks]If the position of equilibrium shifts to the right when the temperature is changed, is the temperature being increased or decreased? Explain your reasoning using the ΔH value.
Question 376
2 marks · Hard
Answer and see the solution →For the following equilibrium reaction:
State how increasing the temperature will affect the position of equilibrium. Give your answer for both cases: (i) forward reaction is exothermic; (ii) forward reaction is endothermic.
Question 377
1 mark · Easy
Answer and see the solution →State the effect of adding a catalyst on the position of equilibrium in a reversible chemical reaction.
Question 378
3 marks · Easy
Answer and see the solution →(a)A reversible reaction mixture is at equilibrium. A catalyst is added to the system.
Explain what happens to:
(i)[1 mark]the rate at which the equilibrium is reached,
(ii)[1 mark]the position of equilibrium,
(iii)[1 mark]the amount of products at equilibrium.
Question 379
2 marks · Easy
Answer and see the solution →In a reversible reaction at equilibrium, the rate of the forward reaction is 0.6 mol/dm³/s and the rate of the reverse reaction is also 0.6 mol/dm³/s. A catalyst is added and both rates are increased by a factor of 5.
Calculate the new rate of the forward reaction, and state whether the position of equilibrium will change.
Question 380
2 marks · Easy
Answer and see the solution →A student claims that adding a catalyst to a reversible reaction will result in more products being formed at equilibrium. Explain, with reasons, whether the student is correct.