The reaction A(g)⇌B(g)\mathrm{A(g) \rightleftharpoons B(g)}A(g)⇌B(g) has an exothermic forward reaction. Three identical sealed flasks, P, Q and R, each start with 1.00 mol of A. P and Q are at the same temperature, and Q also contains a catalyst. R is at a different temperature from P. The table shows the amount of B in each flask.
| Time / min | 2 | 5 | 10 | 20 |
|---|---|---|---|---|
| Flask P: amount of B / mol | 0.20 | 0.40 | 0.60 | 0.60 |
| Flask Q: amount of B / mol | 0.45 | 0.60 | 0.60 | 0.60 |
| Flask R: amount of B / mol | 0.35 | 0.45 | 0.45 | 0.45 |
Which deduction about flask R is correct?
R was hotter than P, as a higher temperature raises the rate and favours the reverse reaction
R was cooler than P, as a lower temperature favours the endothermic reverse reaction
R had a catalyst, as a catalyst raises the rate and moves the position to the left
R was hotter than P, as a higher temperature raises the rate and favours the forward reaction
45 exam-style questions on Edexcel GCSE Chemistry 5.2 Reversible reactions and equilibria, covering 5.2.1 Reversible reactions and dynamic equilibrium, 5.2.2 The Haber process, and 5.2.3 Changing the position of a dynamic equilibrium. Each one has a worked solution and a mark scheme showing where the marks go.