Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Halogens
86 practice questions
Topics covered
Practice questions
31–40 of 86
Question 31
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 32
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 33
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 34
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 35
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.
Question 36
2 marks · Hard
Answer and see the solution →Potassium bromide solution is added to separate solutions of chlorine and iodine. Describe what you would observe in each case, and explain why these observations are different.
Question 37
5 marks · Hard
Answer and see the solution →A student adds solutions of bromine and iodine to separate samples of potassium chloride and potassium iodide. The results are summarised below:
Summary of Observed Colour Changes Added halogen solution Potassium chloride solution Potassium iodide solution Bromine No change Brown colour appears Iodine No change No change Use the information and your knowledge of halogen reactivity to answer the following.
(a)[1 mark]Write a balanced chemical equation for the reaction that occurs when bromine solution is added to potassium iodide solution.
(b)[2 marks]Explain why there is no reaction when bromine solution is added to potassium chloride solution.
(c)[2 marks]Describe and explain the difference in the observations when bromine and iodine solutions are added to potassium iodide solution.
Question 38
2 marks · Hard
Answer and see the solution →State and explain the trend in the reactivity of chlorine, bromine and iodine as shown by their displacement reactions.
Question 39
1 mark · Easy
Answer and see the solution →Name the ion that is displaced when bromine water is added to sodium iodide solution.
Question 40
3 marks · Easy
Answer and see the solution →Fluorine can react with potassium chloride solution in a displacement reaction.
(a)[2 marks]State whether potassium chloride reacts with bromine water. Explain your answer.
(b)[1 mark]Explain why fluorine always acts as an oxidising agent in these types of reactions.