Chemistry 0620 · IGCSE · Reversible reactions and equilibrium

Reversible reactions and equilibrium — practice question

The equation for the reversible reaction of hydrogen with iodine to produce hydrogen iodide is given. The colours of the reactants and products are shown. $\text{H}_2(g) + \text{I}_2(g) \rightleftharpoons 2\text{HI}(g)$. The forward reaction releases heat. Which statement is correct?

  • AAn increase in pressure has no effect on the equilibrium position.
  • BThe purple colour fades when the reaction mixture is heated.
  • CWhen equilibrium is reached, both forward and reverse reactions stop.
  • DWhen more hydrogen gas is added, the purple colour increases.

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