The graph below shows the progress of the acid-catalysed hydrolysis of ethyl acetate, measuring the concentration of ethanol produced over time.
Calculate the mean rate of reaction between 40 and 120 minutes.
Use the graph and the equation:
Mean rate of reaction=Change in concentration of productTime taken\text{Mean rate of reaction} = \frac{\text{Change in concentration of product}}{\text{Time taken}}Mean rate of reaction=Time takenChange in concentration of product
Give your answer to 3 significant figures.