A reversible reaction takes place in a sealed vessel.
A(g)⇌B(g) \mathrm{A(g) \rightleftharpoons B(g)} A(g)⇌B(g)The amounts of A and B are measured at different times. At 30 minutes, the amounts are measured immediately before and immediately after 20 mmol of B is injected into the vessel.
| Time / min | Amount of A / mmol | Amount of B / mmol | Event |
|---|---|---|---|
| 10 | 40 | 60 | |
| 20 | 40 | 60 | |
| 30 | 40 | 60 | before B is added |
| 30 | 40 | 80 | after 20 mmol of B is added |
| 40 | 45 | 75 | |
| 50 | 48 | 72 | |
| 60 | 48 | 72 |
Explain what the results show about the reaction from 10 to 30 minutes and after B is added.
124 exam-style questions on OCR GCSE Chemistry 5.3 Equilibria, covering 5.3.1 Reversible reactions and dynamic equilibrium and 5.3.2 Changing the position of equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.