Limestone in industry British Geological Survey
The uses of limestone in industry. When acid and limestone react, the limestone and the acid change. For example, when limestone (CaCO 3) is added to hydrochloric acid (HCl), they form calcium chloride, water and carbon dioxide:. 2HCl + CaCO 3 → CaCl 2 + H 2 O + CO 2. This results in stone weathering of limestone in nature, but another way of looking at this is that the acid is neutralised.