A student investigates the decomposition of hydrogen peroxide, H2O2\text{H}_2\text{O}_2H2O2, to produce oxygen gas, O2\text{O}_2O2, and water, H2O\text{H}_2\text{O}H2O, using different sizes of manganese(IV) oxide catalyst granules.
In each of three experiments, D, E, and F, she uses the same volume and concentration of hydrogen peroxide but a different size of catalyst granules.
Look at the graph of her results.
a.[1]
Look at the line for experiment E on the graph. When is the rate of reaction greatest? Choose your answer from the list:
- 0 – 20 seconds
- 20 – 40 seconds
- 40 – 60 seconds
- 60 – 80 seconds
b.[3]
Look at the line for experiment F. Calculate the rate of reaction during the first 70 seconds. Give your answer to 2 significant figures.