A sealed container holds gases P, Q and R at dynamic equilibrium.
2P(g)+Q(g)⇌3R(g) \mathrm{2P(g) + Q(g) \rightleftharpoons 3R(g)} 2P(g)+Q(g)⇌3R(g)Measurements show that the forward reaction uses 5.0 × 1020 molecules of P each second.
How many molecules of R break down in the reverse reaction each second?
5.0×10205.0 \times 10^{20}5.0×1020
7.5×10207.5 \times 10^{20}7.5×1020
1.5×10211.5 \times 10^{21}1.5×1021
2.5×10202.5 \times 10^{20}2.5×1020
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.