Solid X reacts with liquid Y to form gas Z. A student carries out two experiments using differently sized pieces of X. Liquid Y is in excess and all other conditions are the same.

Experiment	Mass of X in g	Total exposed surface area of X in $cm2\mathrm{cm^2}$	Volume of Z after 20 s in $cm3\mathrm{cm^3}$	Final volume of Z in $cm3\mathrm{cm^3}$
P	2.50	18.0	14	50
Q	2.50	72.0	37	not measured

Calculate the mean rate of formation of gas Z during the first 20 s in each experiment.

Explain, using collision theory and the surface area data, why the mean rate is greater in experiment Q.

Give the final volume of gas Z expected in experiment Q. Explain your answer.

Solid X reacts with liquid Y to form gas Z. A student carries out two experiments using differently sized pieces of X. Liquid Y is in excess and all other conditions are the same.

Experiment	Mass of X in g	Total exposed surface area of X in $cm2\mathrm{cm^2}$	Volume of Z after 20 s in $cm3\mathrm{cm^3}$	Final volume of Z in $cm3\mathrm{cm^3}$
P	2.50	18.0	14	50
Q	2.50	72.0	37	not measured

Calculate the mean rate of formation of gas Z during the first 20 s in each experiment.

Explain, using collision theory and the surface area data, why the mean rate is greater in experiment Q.

Give the final volume of gas Z expected in experiment Q. Explain your answer.

8.1 Rates of reaction

Question 27

Markscheme

8.1 Rates of reaction

Question 27

Markscheme

8.1 Rates of reaction

Question 27

8.1 Rates of reaction Questions

8.1 Rates of reaction

Question 27

8.1 Rates of reaction Questions