You can do it like this:
I will confine the answer to a 1st order reaction.
Suppose we have:
For a 1st order reaction we have:
Where k is the rate constant.
This can be expressed in terms of the rate of disappearance of A :
Rearranging and applying integration between 0 and t gives:
You can see that this is a straight line graph of the form
This means if we plot
Here is an example for the breakdown of ozone by light:
See if you can measure the gradient yourself to give you -k.
If you read off the intercept i.e the point where the graph cuts the y axis, this will give you the value of
You can get