Substance P changes into substance Q in a reversible reaction in a sealed vessel.
P⇌Q \mathrm{P \rightleftharpoons Q} P⇌QThe masses of P and Q are measured at regular intervals.
| Time (minutes) | Mass of P (g) | Mass of Q (g) |
|---|---|---|
| 0 | 10.0 | 0.0 |
| 2 | 7.0 | 3.0 |
| 4 | 6.0 | 4.0 |
| 6 | 6.0 | 4.0 |
| 8 | 6.0 | 4.0 |
Describe and explain the pattern shown by the measurements. In your explanation, link the measurements to what happens in each direction of the reaction.
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.