A student investigates the rate of a reaction that is first-order with respect to nitric acid, HNO3(aq)\text{HNO}_3\text{(aq)}HNO3(aq).
- The student carries out a reaction using 0.750 mol dm−3 HNO3(aq)0.750\text{ mol dm}^{-3}\text{ HNO}_3\text{(aq)}0.750 mol dm−3 HNO3(aq). The initial rate is 1.20×10−3 mol dm−3 s−11.20 \times 10^{-3}\text{ mol dm}^{-3}\text{ s}^{-1}1.20×10−3 mol dm−3 s−1.
- The student dilutes a different sample of 0.750 mol dm−3 HNO3(aq)0.750\text{ mol dm}^{-3}\text{ HNO}_3\text{(aq)}0.750 mol dm−3 HNO3(aq). The pH of this diluted acid is 1.401.401.40.
- The student repeats the reaction using the same volume of this diluted acid.