Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Unit
Physical Chemistry
442 practice questions
Topics covered
Practice questions
131–140 of 188 · Normal
Question 131
2 marks · Normal
Answer and see the solution →State two reasons why no substances can escape from a sealed container during a reversible reaction.
Question 132
4 marks · Normal
Answer and see the solution →A student heats ammonium chloride in a sealed test tube. The following reversible reaction occurs:
Answer the following questions about this experiment.
(a)[1 mark]State what is meant by a sealed container in this experiment.
(b)[1 mark]Describe what happens to NH3 and HCl in the sealed container after heating.
(c)[1 mark]Explain why both the forward and reverse reactions occur in this setup.
(d)[1 mark]Explain how equilibrium is reached during the reaction.
Question 133
3 marks · Normal
Answer and see the solution →A sample of solid ammonium chloride, , is heated in a sealed tube. The decomposition reaction is:
Suppose you start with 0.80 mol of in the tube. After reaching equilibrium, 0.32 mol of remains.
Calculate the amount (in mol) of ammonia gas, , present at equilibrium.
Question 134
4 marks · Normal
Answer and see the solution →Methanol can be produced from carbon monoxide and hydrogen:
This reaction is reversible and carried out in a sealed container.
(a)[2 marks]Explain what happens to the position of equilibrium when the temperature is increased, assuming the forward reaction is exothermic.
(b)[2 marks]Describe how increasing the pressure will affect the position of equilibrium.
Question 135
3 marks · Normal
Answer and see the solution →Ethene (3) reacts reversibly with steam to form ethanol (85):
The forward reaction is exothermic.
Explain, with reasons, the effect of decreasing both temperature and pressure on the yield of ethanol at equilibrium.
Question 136
2 marks · Normal
Answer and see the solution →State and explain what would happen to the position of equilibrium if the pressure is decreased for the following reaction in a sealed container:
Question 137
4 marks · Normal
Answer and see the solution →Ammonia is made in the Haber process:
The forward reaction is exothermic.
(a)[2 marks]Explain what happens to the yield of ammonia if the temperature is increased.
(b)[2 marks]Describe and explain the effect of increasing pressure on the position of equilibrium.
Question 138
2 marks · Normal
Answer and see the solution →A reversible reaction is shown below: The forward reaction is exothermic. Explain what will happen to the position of equilibrium if the temperature is increased.
Question 139
3 marks · Normal
Answer and see the solution →Hydrogen iodide is formed in the reversible reaction: The forward reaction is endothermic. A closed container starts with 0.50 mol of hydrogen, 0.50 mol of iodine, and no hydrogen iodide. The mixture is allowed to reach equilibrium. State and explain what will happen to the amount of hydrogen iodide present at equilibrium if the pressure is doubled (assume temperature is kept constant and all substances are gases, with equal volumes occupied).
Question 140
1 mark · Normal
Answer and see the solution →For the equilibrium reaction:
The forward reaction is exothermic. What will happen to the concentration of PCl5 if the temperature is increased at constant pressure?
- A.It will increase.
- B.It will decrease.
- C.It will stay the same.
- D.It will fluctuate.