Memorisation

Question 1

what practical would you do to show how rate is affected by the surface area of a solid

Answer 1

Calcium carbonate chips with hydrochloric acid. Measure volume of CO2 output over period of time. more CO2 output = higher rate

Question 2

what practical would you do to show how rate is affected by concentration of a solution

Answer 2

React sodium thiosulphate solution with hydrochloric acid. this creates sulphur so that after a while you can’t see through the mixture to the cross at the bottom. rate = 1 / time taken (for the cross to disappear)

Question 3

what practical would you do to show how rate is affected by temperature

Answer 3

reacting magnesium with hydrochloric acid.
input: temperature of HCl
output: time taken for Mg to disappear
rate = 1/time taken

Question 4

what practical would you use to show how rate is affected by catalysts

Answer 4

decomposition of hydrogen peroxide, catalysed by manganese oxide. rate = volume O2 produced / time