Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Halogens
86 practice questions
Topics covered
Practice questions
31–35 of 35 · Normal
Question 31
4 marks · Normal
Answer and see the solution →This question is about how halogens react by gaining electrons.
(a)[1 mark]Describe what happens to a bromine atom when it reacts to form a bromide ion.
(b)[3 marks]Explain, using electron arrangement, why it is easier for chlorine to form an ion than bromine.
Question 32
3 marks · Normal
Answer and see the solution →Iodine (I2) is a solid at room temperature, and its melting point is 114 °C. Its colour as a solid is purple-black. Astatine (At) is the element below iodine in Group 7 and has not been isolated, but its properties can be predicted from group trends.
Predict the following properties of astatine (At2) based on your knowledge of halogen group trends:
(a)[1 mark]State the physical state (solid, liquid or gas) in which astatine would exist at room temperature.
(b)[1 mark]Estimate whether the melting point of astatine would be higher or lower than that of iodine. Explain your answer.
(c)[1 mark]State and explain what colour (compared to iodine) you would expect astatine to be as a solid.
Question 33
6 marks · Normal
Answer and see the solution →(a)[1 mark]State the physical state and color of chlorine at room temperature.
(b)[2 marks]Describe what you would observe when chlorine gas is bubbled through a solution of potassium iodide.
(c)[2 marks]Write a balanced chemical equation for the reaction in part b.
(d)[1 mark]Explain why this reaction happens in terms of the reactivity of the halogens.
Question 34
6 marks · Normal
Answer and see the solution →(a)[2 marks]Explain, with the aid of a balanced equation, what happens when sodium reacts with bromine.
(b)A student adds bromine water to a solution of potassium iodide in a test tube.
(i)[1 mark]State what you would observe.
(ii)[2 marks]Write a balanced equation for the reaction.
(iii)[1 mark]Explain why bromine can displace iodine in this reaction but not chlorine.
Question 35
6 marks · Normal
Answer and see the solution →A teacher wants to compare the reactivity of chlorine, bromine and iodine using displacement reactions with metal halide solutions.
(a)[2 marks]Chlorine is bubbled into a solution of potassium bromide. The solution turns orange. Explain why this colour change occurs. Include what is formed.
(b)[2 marks]A student adds bromine water to a solution of potassium chloride. No visible change is seen. Explain this observation, referring to relative reactivity.
(c)[2 marks]State and explain which halogen is the least reactive out of chlorine, bromine and iodine.