You can work out the order with respect to a particular reactant using a rate-concentration graph. You can make a rate-concentration graph from a concentration time graph.
- Find the gradient at various points along the concentration-time graph.
- Plot the points and join them up with a line/curve.
The shape of the rate-concentration graph tells you the order
ZERO ORDER: a horizontal line on a rate-concentration graph means changing the concentration doesnt change the rate so the order is zero.