Chlorine and bromine are elements in Group 7 of the Periodic Table.
Both elements exist in a number of different oxidation numbers and therefore are
involved in many redox reactions.
(a) Write an equation for the reaction between chlorine and cold, dilute aqueous
sodium hydroxide. State symbols are not required.
(1)
(b) Chlorine dioxide reacts with cold, dilute aqueous sodium hydroxide.
The ionic equation for the reaction is:
2ClO (aq) + 2OH−(aq) → ClO –(aq) + ClO –(aq) + H O(l)
Question
Mathematics
Edexcel2019
This question is about some redox reactions of chlorine, bromine and iodine.
(a) An excess of aqueous potassium bromide was added to chlorine water and the
solution turned orange.
(i) Write an equation for this reaction. State symbols are not required.
(1)
(ii) Silver nitrate solution was added to the mixture in (a) and excess
dilute ammonia solution was then added to the precipitate formed.
Only some of the precipitate dissolved.
Deduce why only some of the precipitate dissolved.
(3)
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(iii) Aqueous potassium bromide was added to aqueous iodine, instead of
chlorine water. There was no reaction.
Give a reason why no reaction occurred.
(1)
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Question
Mathematics
Edexcel2017
This question is about halogens and redox reactions.
(a) The boiling temperatures of three halogens are shown in the table.
Boiling temperature
Halogen
/ °C
chlorine –35
bromine 59
iodine 184
Explain why the boiling temperatures increase from chlorine to iodine.
(2)
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