1. Understand the data
Initial reaction rate describes how quickly a reaction starts. This illustrative data example pairs four starting concentrations with gas-production rates, with all other conditions kept constant.
| Concentration mol dm⁻³ | Initial rate cm³ s⁻¹ |
|---|---|
| 0.10 | 0.42 |
| 0.20 | 0.81 |
| 0.30 | 1.25 |
| 0.40 | 1.62 |
Compare the first and last rows: both concentration and rate increase. To find the factor of increase, divide the final value by the initial value.
An original teaching example from our published IB data-analysis guide; not an official exam question. The basic data-analysis skill is useful across exam programmes.