A reaction uses a dissolved reactant and produces a gas. The gas escapes from the reaction mixture.
A student recorded the time taken for the mass of the reaction mixture to decrease by 1.20 g. All other conditions were kept the same.
| Initial concentration of dissolved reactant in mol/dm3\text{mol/dm}^3mol/dm3 | Time for mass to decrease by 1.20 g in s\text{s}s |
|---|---|
| 0.25 | 160 |
| 0.40 | 100 |
The student claimed that the mean rate of reaction was directly proportional to the initial concentration of the dissolved reactant.
Calculate the mean rate at each concentration. Use your answers to explain why the results support the student's claim.
Assume that the student's claim is correct.
Calculate the time taken for the mass to decrease by 1.20 g when the initial concentration is 0.70 mol/dm3.
127 exam-style questions on AQA GCSE Chemistry 6.1 Rate of reaction, covering 6.1.1a Calculating rates of reactions, 6.1.1b Gradient of a tangent as rate, 6.1.2 Factors which affect the rates of chemical reactions, 6.1.3 Collision theory and activation energy, and 6.1.4 Catalysts. Each one has a worked solution and a mark scheme showing where the marks go.