Paper 2 H - SAMPLE SET 1 Q16 Answers
16) Zinc and dilute sulfuric acid react to make hydrogen.
Inga measures the rate of this reaction by measuring the loss in mass of the reaction mixture.
She finds that the change in mass is very small and difficult to measure.
(a) Draw a labelled diagram to show a better way of measuring the rate of this reaction. [3]
(b) The reaction between zinc and dilute sulfuric acid is slow.
Inga decides to try and find a catalyst for this reaction.
She tests four possible substances.
Each time she adds 0.5 g of the substance to 1.0 g of zinc and 25 cm3 of dilute sulfuric acid.
Look at her table of results.
She finds that the change in mass is very small and difficult to measure.
(a) Draw a labelled diagram to show a better way of measuring the rate of this reaction. [3]
(b) The reaction between zinc and dilute sulfuric acid is slow.
Inga decides to try and find a catalyst for this reaction.
She tests four possible substances.
Each time she adds 0.5 g of the substance to 1.0 g of zinc and 25 cm3 of dilute sulfuric acid.
Look at her table of results.
(i) It is important to do the reaction with only zinc and dilute sulfuric acid.
Explain why. [1]
(ii) It is important to do all of the reactions with the same concentration of acid.
Explain why. [1]
(iii) Which of the substances could be a catalyst for the reaction between zinc and dilute sulfuric acid?
……………………………………………
Explain your answer. [2]
(iv) There is not enough evidence to confirm which substance is a catalyst.
Suggest an extra piece of experimental evidence that could be collected to confirm which substance is a catalyst. [1]
(v) Inga does the experiment with copper, zinc and dilute sulfuric acid again.
This time she uses a lump of copper rather than copper powder.
Predict, with reasons, the relative rate of reaction. [2]
(Total for Question 16 = 10 marks)
Explain why. [1]
(ii) It is important to do all of the reactions with the same concentration of acid.
Explain why. [1]
(iii) Which of the substances could be a catalyst for the reaction between zinc and dilute sulfuric acid?
……………………………………………
Explain your answer. [2]
(iv) There is not enough evidence to confirm which substance is a catalyst.
Suggest an extra piece of experimental evidence that could be collected to confirm which substance is a catalyst. [1]
(v) Inga does the experiment with copper, zinc and dilute sulfuric acid again.
This time she uses a lump of copper rather than copper powder.
Predict, with reasons, the relative rate of reaction. [2]
(Total for Question 16 = 10 marks)
Answers
