Substances A and B react in solution at a constant temperature. The initial rate of reaction was studied in three experiments by measuring the change in concentration of A over the first ten seconds of the reaction. The data obtained are shown in Table 1.
| Experiment | Time after mixing / s\text{s}s | Concentration of A / mol dm−3\text{mol dm}^{-3}mol dm−3 | Concentration of B / mol dm−3\text{mol dm}^{-3}mol dm−3 |
|---|---|---|---|
| 1 | 0 | 2.00×10−22.00 \times 10^{-2}2.00×10−2 | 1.50×10−21.50 \times 10^{-2}1.50×10−2 |
| 10.0 | 1.80×10−21.80 \times 10^{-2}1.80×10−2 | not measured | |
| 2 | 0 | 4.00×10−24.00 \times 10^{-2}4.00×10−2 | 1.50×10−21.50 \times 10^{-2}1.50×10−2 |
| 10.0 | 3.60×10−23.60 \times 10^{-2}3.60×10−2 | not measured | |
| 3 | 0 | 1.00×10−21.00 \times 10^{-2}1.00×10−2 | 3.00×10−23.00 \times 10^{-2}3.00×10−2 |
| 10.0 | 0.60×10−20.60 \times 10^{-2}0.60×10−2 | not measured |
Calculate the initial rate of reaction of A in experiments 2 and 3 to complete Table 2 below.
| Experiment | Initial rate of reaction of A / mol dm−3 s−1\text{mol dm}^{-3}\text{ s}^{-1}mol dm−3 s−1 |
|---|---|
| 1 | 2.0×10−42.0 \times 10^{-4}2.0×10−4 |
| 2 | |
| 3 |
Determine the order of reaction with respect to A and the order of reaction with respect to B.
A reaction between substances Y and Z was second order with respect to Y and first order with respect to Z. At a given temperature, the initial rate of reaction was 1.44×10−3 mol dm−3 s−11.44 \times 10^{-3}\text{ mol dm}^{-3}\text{ s}^{-1}1.44×10−3 mol dm−3 s−1 when the initial concentration of Y was 1.20×10−2 mol dm−31.20 \times 10^{-2}\text{ mol dm}^{-3}1.20×10−2 mol dm−3 and the initial concentration of Z was 2.00×10−2 mol dm−32.00 \times 10^{-2}\text{ mol dm}^{-3}2.00×10−2 mol dm−3.
Calculate a value for the rate constant, kkk, for the reaction at this temperature. Give the units for kkk.
