Hydrochloric acid reacts with solid B - Edexcel - GCSE Chemistry Combined Science - Question 4 - 2021 - Paper 1
Question 4
Hydrochloric acid reacts with solid B.
Solid B is an alkali.
A student carries out an experiment to see how the pH changes when different masses of solid B are a... show full transcript
Worked Solution & Example Answer:Hydrochloric acid reacts with solid B - Edexcel - GCSE Chemistry Combined Science - Question 4 - 2021 - Paper 1
Step 1
Give a safety precaution that should be taken during the experiment.
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Answer
Always wear safety goggles and gloves when handling hydrochloric acid to protect your eyes and skin from any splashes.
Step 2
Give an improvement to step 4 that would produce more accurate results.
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Answer
Instead of adding a half spatula of solid B in one go, it would be better to add it in smaller increments (e.g., a quarter of a spatula), allowing for more precise control of pH changes.
Step 3
What is the most likely change in pH during the experiment?
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Answer
The most likely change in pH during the experiment is from 1 to 7, as the alkali solid B neutralizes the hydrochloric acid.
Step 4
State the colour change.
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colour at start in acid: red; colour at end: yellow/orange.
Step 5
Give the name of the piece of apparatus labelled X.
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Answer
The piece of apparatus labelled X is a gas jar.
Step 6
What is the name of this piece of apparatus?
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Answer
The piece of apparatus labelled Y is an electrode.
Step 7
Give one reason why graphite is a suitable material to make Y.
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Graphite is a suitable material to make Y because it is a good conductor of electricity.
Step 8
Complete the balanced equation for the reaction that occurs.
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