Yellow chromate ions and orange dichromate ions are in equilibrium in solution: 2CrO42−(aq)+2H+(aq)⇌Cr2O72−(aq)+H2O(l)\mathrm{2CrO_{4}^{2-}(aq) + 2H^{+}(aq) \rightleftharpoons Cr_{2}O_{7}^{2-}(aq) + H_{2}O(l)}2CrO42−(aq)+2H+(aq)⇌Cr2O72−(aq)+H2O(l)
Statement 1: adding dilute sulfuric acid makes the solution more orange
Statement 2: adding sodium hydroxide solution makes the solution more yellow, because OH−\mathrm{OH^{-}}OH− ions remove H+\mathrm{H^{+}}H+ ions
Statement 3: adding a catalyst makes the solution more orange, because dichromate ions then form faster
Which statements are correct?
1 only
1 and 2 only
2 and 3 only
1, 2 and 3
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.