The rate equation for the reaction between compounds P\text{P}P and Q\text{Q}Q is:
rate=k[P]2[Q] \text{rate} = k[\text{P}]^2[\text{Q}] rate=k[P]2[Q]In an experiment, the concentration of P\text{P}P was monitored over time, starting with an initial concentration of 0.60 mol dm−30.60\text{ mol dm}^{-3}0.60 mol dm−3.
A tangent to the concentration-time curve drawn at t=0 st = 0\text{ s}t=0 s intersects the time axis (where [P]=0.00 mol dm−3[\text{P}] = 0.00\text{ mol dm}^{-3}[P]=0.00 mol dm−3) at t=15.0 st = 15.0\text{ s}t=15.0 s. Calculate the initial rate of the reaction.
The experiment was repeated at the same temperature and with the same initial concentration of Q\text{Q}Q but with a different initial concentration of P\text{P}P. The new initial rate was 1.961.961.96 times greater than in the original experiment. Calculate the new initial concentration of P\text{P}P.
32 exam-style questions on AQA A Level Chemistry Rate equations (A-level only), covering Rate equations (A-level only) and Determination of rate equation (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.