An inorganic chemistry researcher studies the kinetics of the following reaction in aqueous solution at a constant temperature of 298 K298\text{ K}298 K:
P(aq)+2Q(aq)+2R(aq)→S(aq)+2T(aq) \text{P}(\text{aq}) + 2\text{Q}(\text{aq}) + 2\text{R}(\text{aq}) \rightarrow \text{S}(\text{aq}) + 2\text{T}(\text{aq}) P(aq)+2Q(aq)+2R(aq)→S(aq)+2T(aq)The researcher measures the initial rate of reaction across four experiments with varying initial concentrations of the reactants. The results are summarized in the table below:
| Experiment | [P][\text{P}][P] / mol dm−3\text{mol dm}^{-3}mol dm−3 | [Q][\text{Q}][Q] / mol dm−3\text{mol dm}^{-3}mol dm−3 | [R][\text{R}][R] / mol dm−3\text{mol dm}^{-3}mol dm−3 | Initial rate / mol dm−3 s−1\text{mol dm}^{-3}\text{ s}^{-1}mol dm−3 s−1 |
|---|---|---|---|---|
| 1 | 2.00 × 10-2 | 1.50 × 10-2 | 1.00 × 10-2 | 3.60 × 10-6 |
| 2 | 2.00 × 10-2 | 3.00 × 10-2 | 1.00 × 10-2 | 1.44 × 10-5 |
| 3 | 2.00 × 10-2 | 3.00 × 10-2 | 3.00 × 10-2 | 1.44 × 10-5 |
| 4 | 4.00 × 10-2 | 1.50 × 10-2 | 2.00 × 10-2 | 7.20 × 10-6 |
Explain how the reaction order with respect to each reactant can be determined from these results. Hence, determine the rate equation and the rate constant (including units) for this reaction.
29 exam-style questions on OCR A A Level Chemistry How fast?. Each one has a worked solution and a mark scheme showing where the marks go.