Question

If you want to increase the pH of the stomach from 1 to 2 using an antacid tablet, how many grams of CaCO3 will be required to change the pH value? Assume the acid is HCl and you have a 1L stomach value

Answer 1

1 = -log (H^+) so for pH 1, (H^+) = 0.1M and for 1 L of that, mols HCl = M x L = 0.1 x 1 = 0.1 mol.

2 = -log (H^+)
(H^+) = 0.01 M and mols HCl = 0.01M x 1 L = 0.01 mols.

Then 0.1 mol HCl - 0.01 mol HCl = 0.09 mols HCl to be removed.

2HCl + CaCO3 ==> CaCl2 + H2O + CO2

mols HCl = 0.09.
mols CaCO3 = 1/2 that or 0.045
g CaCO = mols CaCO3 x molar mass CaCO3 = ?