Chemistry · Oct / Nov 2025 · Paper 12 · Question 7

Powdered calcium carbonate reacts with dilute hydrochloric acid to produce calcium chloride, water and carbon dioxide. What is the correct ionic equation, including state symbols, for this reaction?

1. ACaCO3(s) + 2HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g)
2. BCaCO3(s) + 2H+(aq) → Ca2+(aq) + H2O(l) + CO2(g)
3. CCa2+(aq) + CO3^2–(aq) + 2H+(aq) → Ca2+(aq) + H2O(l) + CO2(g)
4. DCO3^2–(aq) + 2H+(aq) → H2O(l) + CO2(g)

As printed in the paper