Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Section
Displacement reactions involving the halogens
19 practice questions
Practice questions
1–8 of 8 · Normal
Question 1
2 marks · Normal
Answer and see the solution →State what you would observe when chlorine water is added to a solution of potassium iodide. Write the chemical equation for the reaction.
Question 2
4 marks · Normal
Answer and see the solution →A student investigates the reactivity of three halogens: chlorine, bromine and iodine, using solutions of their salts.
(a)[2 marks]Explain, with an equation, what happens when bromine solution is added to potassium iodide solution.
(b)[2 marks]The student adds iodine solution to potassium chloride solution. State and explain the observation.
Question 3
3 marks · Normal
Answer and see the solution →Explain why chlorine can displace bromine from potassium bromide solution, but bromine cannot displace chlorine from potassium chloride solution. In your answer, refer to the reactivity trend of halogens.
Question 4
4 marks · Normal
Answer and see the solution →The results below show the observed colour changes when halogen solutions are mixed with different potassium halide solutions.
Observed colour change when halogen solutions are added to potassium halide solutions. Added halogen solution Potassium halide solution Observation Chlorine (Cl2) Potassium bromide (KBr) orange Bromine (Br2) Potassium iodide (KI) brown Iodine (I2) Potassium chloride (KCl) no change (a)[1 mark]Which halogen is the most reactive? Give evidence from the table.
(b)[1 mark]Write a balanced chemical equation for the reaction between bromine solution and potassium iodide solution.
(c)[2 marks]Predict the result if chlorine solution is added to potassium iodide solution. Explain your answer.
Question 5
1 mark · Normal
Answer and check →Which mixture will result in a visible colour change, indicating a displacement reaction?
- A.Chlorine solution and potassium bromide solution
- B.Iodine solution and potassium chloride solution
- C.Bromine solution and potassium chloride solution
- D.Iodine solution and potassium bromide solution
Question 6
2 marks · Normal
Answer and see the solution →Write the balanced equation for the reaction between chlorine and potassium bromide. State the colour change seen during the reaction.
Question 7
4 marks · Normal
Answer and see the solution →A student investigates halogen displacement reactions.
(a)[1 mark]Describe what the student would see when bromine solution is added to potassium chloride solution.
(b)[1 mark]Explain your answer to part (a).
(c)[1 mark]Write a balanced equation for the reaction (if any) between iodine solution and potassium bromide solution.
(d)[1 mark]State the order of reactivity of chlorine, bromine and iodine.
Question 8
3 marks · Normal
Answer and see the solution →A student adds chlorine water to 40.0 cm³ of potassium iodide solution and observes the solution turns brown because iodine is produced. Assume the following equation:
The concentration of the potassium iodide solution is 0.20 mol/dm³.
(a)[1 mark]Calculate the number of moles of potassium iodide present in 40.0 cm³ of the solution. Give your answer to 2 significant figures.
(b)[1 mark]Using the equation above, calculate the maximum number of moles of iodine that can be produced from this amount of potassium iodide. Give your answer to 2 significant figures.
(c)[1 mark]State the observation you would expect if bromine water was added to potassium chloride solution instead of chlorine water to potassium iodide solution.