Pearson Edexcel International GCSE (9–1) · CHEMISTRY · Chapter
The Halogens
86 practice questions
Topics covered
Practice questions
71–80 of 86
Question 71
2 marks · Normal
Answer and see the solution →State what you would observe if chlorine water is added to a solution of sodium iodide. Explain your answer.
Question 72
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 73
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 74
2 marks · Hard
Answer and see the solution →Astatine is the halogen below iodine in Group 7. Predict the colour and state you would expect for astatine at room temperature, based on group trends.
Question 75
5 marks · Hard
Answer and see the solution →This question is about explaining halogen reactivity in terms of electronic configuration.
(a)[1 mark]State, in terms of electron shells, the difference in the position of the outer electrons of a chlorine atom and a bromine atom.
(b)[2 marks]Explain, in terms of electronic configuration, why a chlorine atom is more reactive than a bromine atom.
(c)[1 mark]A chlorine atom reacts to form a chloride ion. Write the electron configuration for the chloride ion.
(d)[1 mark]Using your answers and knowledge of shells, describe what happens, in terms of electrons, when bromine forms a bromide ion.
Question 76
2 marks · Hard
Answer and see the solution →Astatine is the element below iodine in Group 7 of the Periodic Table.
Predict the colour and state of astatine at room temperature. Justify your predictions using group trends.
Question 77
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 78
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 79
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 80
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.