This question is about gases - Edexcel - GCSE Chemistry - Question 3 - 2022 - Paper 1
Question 3
This question is about gases.
(a) When sodium is added to water, hydrogen gas is produced.
Which observation shows that a gas has been produced?
A a white preci... show full transcript
Worked Solution & Example Answer:This question is about gases - Edexcel - GCSE Chemistry - Question 3 - 2022 - Paper 1
Step 1
When sodium is added to water, hydrogen gas is produced. Which observation shows that a gas has been produced?
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Answer
The correct observation is B: effervescence is seen. Effervescence indicates the formation of gas bubbles, which is a sign that hydrogen gas is being released when sodium reacts with water.
Step 2
Which gas bleaches damp litmus paper?
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Answer
The gas that bleaches damp litmus paper is B: chlorine. Chlorine reacts with the dye in litmus paper, leading to its bleaching effect.
Step 3
When calcium carbonate is heated, it decomposes. Calculate the mass of carbon dioxide that has been released.
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Answer
First, determine the mass of carbon dioxide released:
