Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Physical Chemistry
442 practice questions
Topics covered
Practice questions
151–160 of 188 · Normal
Question 151
3 marks · Normal
Answer and see the solution →The following reaction is allowed to reach equilibrium in a sealed container:
The number of gaseous molecules on each side of the equation is different.
Explain, with calculations, why increasing the pressure will affect this equilibrium, and state which side the equilibrium will shift towards. Use the number of moles of gas in your answer.
Question 152
2 marks · Normal
Answer and see the solution →State how changing the temperature affects the position of equilibrium in a reversible reaction.
Question 153
4 marks · Normal
Answer and see the solution →For the following reversible reaction, answer the questions below:
(a)[1 mark]Is the forward reaction exothermic or endothermic? Explain your reasoning.
(b)[2 marks]What will happen to the position of equilibrium if the temperature is increased? Explain your answer.
(c)[1 mark]State whether more SO3 or more SO2 will be present at equilibrium if the temperature is decreased. Give a reason for your answer.
Question 154
3 marks · Normal
Answer and see the solution →A reversible reaction is shown below.
Calculate the enthalpy change (ΔH) for the reverse reaction. State whether the reverse reaction is exothermic or endothermic.
Question 155
3 marks · Normal
Answer and see the solution →The reaction below reaches equilibrium at a certain temperature:
Explain what will happen to the position of equilibrium if you decrease the temperature. Refer to the direction of the equilibrium shift.
Question 156
4 marks · Normal
Answer and see the solution →The table below shows the percentage of X and Y at equilibrium for a reversible reaction at two temperatures.
Temperature (°C) % X at equilibrium % Y at equilibrium 350 30 70 150 65 35 (a)[1 mark]Describe how the percentage of X changes as temperature decreases.
(b)[2 marks]Which direction of reaction is favoured at lower temperature? Explain your answer using the data.
(c)[1 mark]State whether the formation of X from Y is likely exothermic or endothermic. Give a reason.
Question 157
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 158
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 159
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 160
2 marks · Normal
Answer and see the solution →Explain why adding a catalyst does not change the position of equilibrium in a reversible reaction.