Antacids, such as Tums are used to neutralize this excess acid. The active ingredient in Tums is calcium carbonate, CaCO3, a base.

What pH are Tums?

The antacid tablets contain calcium carbonate, which is a base (with a pH value of 11).

Are Tums an acid?

Tums are calcuim carbonate, a basic compound that is used to neutralize gastric acid (the acid I mentioned aboved that is produced in your stomach).