In a typical rates experiment, the mass or volume of product is measured at regular time intervals. The results are usually recorded in a table. For example:
|Time / min||Volume of gas produced / cm3|
These results show that the reaction had finished by four minutes. No more gas was produced after that point.
However, the rate decreased during the reaction as the volume of gas produced decreased as the time increased.
The rate of reaction can be analysed by plotting a graph of amount of product against time. The graph below shows this for two reactions.
Compared to the slow reaction, the graph line for the faster reaction: