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Zinc and dilute sulfuric acid react to make hydrogen - OCR Gateway - GCSE Chemistry - Question 16 - 2019 - Paper 4
Question 16
Zinc and dilute sulfuric acid react to make hydrogen. Zn(s) + H₂SO₄(aq) → ZnSO₄(aq) + H₂(g) A student measures the rate of this reaction by measuring the loss in ma... show full transcript
Worked Solution & Example Answer:Zinc and dilute sulfuric acid react to make hydrogen - OCR Gateway - GCSE Chemistry - Question 16 - 2019 - Paper 4
Step 1
Draw a labelled diagram to show a better way of measuring the rate of this reaction.
Answer
A suitable diagram could involve a gas syringe connected to the reaction vessel where zinc and dilute sulfuric acid are reacting. The gas syringe will collect the hydrogen gas produced. Labels should include:
- The reaction vessel
- The gas syringe
- The delivery tube connecting the two
- Markings on the gas syringe indicating the volume of gas produced.
Step 2
The reaction between zinc and dilute sulfuric acid is slow.
Answer
The addition of catalysts can enhance the reaction rate. In the results table:
- Copper Powder shows a relative rate of reaction of 10, indicating it acts as an effective catalyst as the colour remains pink.
- Copper(II) Sulfate Powder shows a relative rate of 30, suggesting it is even more effective as it speeds up the reaction significantly, confirmed by the colour change from blue to pink.
- Other substances such as calcium sulfate powder and manganese(IV) oxide showed no change in reaction rate and are ineffective as catalysts.