This question is about salts - AQA - GCSE Chemistry Combined Science - Question 1 - 2022 - Paper 1
Question 1
This question is about salts.
Green copper carbonate and sulfuric acid can be used to produce blue copper sulfate crystals.
1. Excess copper carbonate is added to ... show full transcript
Worked Solution & Example Answer:This question is about salts - AQA - GCSE Chemistry Combined Science - Question 1 - 2022 - Paper 1
Step 1
Excess copper carbonate is added to sulfuric acid. Give three observations you would make.
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Answer
The green solid (copper carbonate) gradually disappears as it reacts with the acid.
A color change is observed as the solution turns blue due to the formation of copper sulfate.
Fizzing or effervescence occurs, indicating the release of gas during the reaction.
Step 2
How can the excess copper carbonate be removed?
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The excess copper carbonate can be removed by filtration, allowing the dissolved copper sulfate solution to pass through while retaining the unreacted copper carbonate.
Step 3
The pH of the solution changes during the reaction. What is the pH of the solution at the end of the reaction?
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The pH of the solution at the end of the reaction is 7, indicating that the reaction produces a neutral solution.
Step 4
Copper carbonate and sulfuric acid react to produce copper sulfate. What type of reaction is this?
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This reaction is classified as a neutralization reaction, where an acid reacts with a base to produce a salt and water.
Step 5
Determine the mass of ammonium nitrate that crystallises on cooling 100 cm³ of this solution from 80 °C to 20 °C.
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At 80 °C, the maximum mass of ammonium nitrate that dissolves is approximately 83 g. At 20 °C, this mass decreases to about 32 g. Therefore, the mass that crystallizes upon cooling is:
