Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Halogens
86 practice questions
Topics covered
Practice questions
21–30 of 36 · Easy
Question 21
3 marks · Easy
Answer and see the solution →The table shows the results of adding halogen solutions to different potassium halide solutions.
Observations of displacement reactions Halogen solution Potassium chloride Potassium bromide Potassium iodide Chlorine water — orange solution brown solution Bromine water — — brown solution Iodine solution — — — (a)[2 marks]State two observations from the table that provide evidence for displacement reactions.
(b)[1 mark]Identify the halide ion displaced by chlorine water from the solutions tested.
Question 22
1 mark · Easy
Answer and see the solution →State which species is reduced in the reaction between chlorine and potassium bromide.
Question 23
3 marks · Easy
Answer and see the solution →Complete the ionic equation for the reaction between bromine water and sodium iodide solution. Include state symbols.
(a)[1 mark]Write the products formed in the reaction.
(b)[2 marks]Write a balanced ionic equation, including state symbols, for the reaction.
Question 24
2 marks · Easy
Answer and see the solution →Bromine water is added to a solution of sodium iodide. Explain, in terms of electron transfer, why bromine acts as an oxidising agent in this reaction.
Question 25
1 mark · Easy
Answer and see the solution →State the colour you would expect for the vapour of bromine at room temperature based on group trends.
Question 26
3 marks · Easy
Answer and see the solution →This question is about why chlorine is more reactive than iodine.
(a)[1 mark]State the charge on the ion formed when a chlorine atom gains an electron.
(b)[2 marks]Describe, using electronic configuration, why a chlorine atom is better at gaining an electron than an iodine atom.
Question 27
2 marks · Easy
Answer and see the solution →Explain, in terms of electronic configuration, why bromine is less reactive than chlorine.
Question 28
3 marks · Easy
Answer and see the solution →Below is a table of some Group 7 elements and their melting points.
Melting points of some halogens Element Melting Point (°C) Fluorine -220 Chlorine -101 Bromine -7 Iodine 114 (a)[1 mark]Describe the trend in melting point as you go down Group 7.
(b)[2 marks]Predict whether astatine would have a higher or lower melting point than iodine. Give a reason for your answer.
Question 29
1 mark · Easy
Answer and see the solution →State how many electron shells are completely full in a chlorine atom.
Question 30
3 marks · Easy
Answer and see the solution →This question is about the properties of the halogens.
(a)[1 mark]What is the formula of the ion formed when iodine forms an ionic salt?
(b)[2 marks]Describe the colour and state of iodine at room temperature.