Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Halogens
86 practice questions
Topics covered
Practice questions
31–36 of 36 · Easy
Question 31
2 marks · Easy
Answer and see the solution →The table below gives the melting points of chlorine and bromine (both Group 7 elements):
Element Melting point (°C) Chlorine -101 Bromine -7 Iodine is the next element down the group after bromine. Use the data to estimate a likely melting point for iodine and explain your reasoning based on group trends.
Question 32
2 marks · Easy
Answer and see the solution →A chlorine atom can react to form a chloride ion. Calculate the total number of electrons in this chloride ion. Explain your answer using the electronic configuration.
Question 33
5 marks · Easy
Answer and see the solution →Chlorine, bromine and iodine are Group 7 elements. In the laboratory, a student mixes chlorine water with potassium iodide solution.
(a)[1 mark]Write the ionic equation for the reaction that occurs between chlorine water and potassium iodide solution.
(b)[1 mark]State what you would observe during this reaction.
(c)[2 marks]Explain why chlorine is able to displace iodine from potassium iodide solution, but bromine cannot.
(d)[1 mark]Predict what you would see if bromine water was added to potassium chloride solution. Explain your answer.
Question 34
5 marks · Easy
Answer and see the solution →A laboratory investigation compares the ability of Group 7 elements to act as oxidising agents. The electronic structures of chlorine and bromine are shown below.
(a)[2 marks]Explain, in terms of electron transfer, why the reaction between chlorine and iodide ions is classed as a redox reaction.
(b)[2 marks]Chlorine is a stronger oxidising agent than bromine. Explain why, using ideas about the electronic configuration of halogen atoms.
(c)[1 mark]State how the reactivity of the halogens changes as you go down the group.
Question 35
5 marks · Easy
Answer and see the solution →Iodine is unable to displace bromine from potassium bromide solution. Use knowledge of redox and electronic structure to answer the following:
(a)Explain, in terms of electron transfer, what occurs to the bromide ions in a displacement reaction with chlorine.
(b)[2 marks]State whether iodine acts as an oxidising agent or reducing agent in displacement reactions, and explain your answer.
(c)[3 marks]Using information about electronic configuration, explain why chlorine is more reactive than bromine.
Question 36
5 marks · Easy
Answer and see the solution →A student adds bromine water to a solution of potassium iodide.
(a)[1 mark]Write the ionic equation for the reaction that takes place.
(b)[2 marks]State and explain what you would observe when bromine water is added to potassium iodide solution.
(c)[2 marks]Predict whether a similar reaction would occur if the student added iodine solution to potassium bromide solution. Explain your answer in terms of halogen reactivity.