A manufacturer tests a solution used to remove a reactive metal coating from test pieces.
Each test piece has the same amount of coating exposed over the same area. The etching solution is in excess in both tests, so all of the coating reacts. The temperature is kept constant.
The rate at which the coating reacts is directly proportional to the concentration of the etching solution.
| Concentration of etching solution (mol/dm³) | Time for all the coating to react (s) |
|---|---|
| 0.60 | 210 |
| 1.50 | not yet known |
Calculate how long it should take for all the coating to react when the concentration of the etching solution is 1.50 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.