6. Fluorine, chlorine, bromine, iodine and astatine are elements in group 7 - Edexcel - GCSE Chemistry Combined Science - Question 6 - 2019 - Paper 1
Question 6
6. Fluorine, chlorine, bromine, iodine and astatine are elements in group 7.
(a) Describe the test to show that a gas is chlorine.
(b) Bromine reacts with hydrog... show full transcript
Worked Solution & Example Answer:6. Fluorine, chlorine, bromine, iodine and astatine are elements in group 7 - Edexcel - GCSE Chemistry Combined Science - Question 6 - 2019 - Paper 1
Step 1
Describe the test to show that a gas is chlorine.
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Answer
To test for chlorine gas, a piece of damp litmus paper can be used. If chlorine is present, it will bleach the damp litmus paper, turning it white.
Step 2
State the name of the solution formed.
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Answer
The solution formed is called hydrogen bromide solution.
Step 3
Predict the colour and state of astatine at room temperature.
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Answer
colour: black;
state: solid.
Step 4
Explain the observations shown in the table.
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Answer
The initial colour of bromine is orange, which changes to brown due to its interaction with the water, leading to the formation of bromine solution that is generally brown in colour. Chlorine starts as pale green and also ends up brown, which might indicate that the chlorine gas dissolves and reacts with other substances in the solution, producing a brown colour. Iodine remains brown throughout because it is already dissolved in the solution, indicating it does not undergo a significant colour change when mixed with water.
Step 5
Write the balanced equation for this reaction.
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