Answer:
Deduce the balanced chemical equation:
CaCO3(s) + 2HCl(aq) > CaCl2 + H2O(l) + CO2(g)
2. Write as ionic species:
Ca2+(aq) + CO3 2- (aq) + 2H+ + 2Cl- > Ca2+(aq)+ 2Cl-(aq) + H2O(l) + CO2(g)
3. Identify ions on the right that also appear on the left, and eliminate them. (As Robert Cruikshank says, these are known as ’spectator ions’ and take no overall part in the reaction):
CO3 2- (aq) + 2H+(aq) > H2O(l) + CO2(g)
This is the balanced ionic equation.