The word formula for the reaction between calcium carbonate and hydrochloric acid is:

Calcium carbonate + Hydrochloric acid → Calcium chloride + Carbon dioxide + Water

Here's the balanced chemical equation for the reaction:

CaCO₃ (s) + 2 HCl (aq) → CaCl₂ (aq) + CO₂ (g) + H₂O (l)