Which is the more effective antacid per gram, NaHCO3 or Mg(OH)2?

Answer 1

The acid present in the stomach is HCl.

The balanced reactions for each are

NaHCO3 + HCl ======> H2CO3 + NaCl where H2CO3 is a weak acid.

Mg(OH)2 + 2HCl ======> MgCl2 + 2H2O

1 g of NaHCO3 has 1 / 84 = 0.012 moles which is equal to the moles of HCl neutralized.

1 g of Mg(OH)2 has 1 / 58 = 0.017 moles but neutralizes 2 x 0.017 moles HCl = 0.034 moles HCl

Mg(OH)2 is the more effective antacid per gram.

I rounded the formula weights of NaHCO3 and Mg(OH)2 to whole numbers.