posted by Marie on .
How many grams of calcium carbonate, CaCO3, do you need in an antacid tablet to neutralize 20 mL of stomach acid? (stomach acid is 0.1 M HCl. There are 3.65g of HCl in 1L of stomach acid or 1g of HCl in 274g of stomach acid).
You have more information in the problem than you need.
Write the equation.
CaCO3 + 2HCl ==> CaCl2 + CO2
mols HCl = M x L = 0.1M x 0.020 L = ?
mols CaCO3 = 1/2 that (from the coefficients in the balanced equation).
Then grams CaCO3 = mols CaCO3 x molar mass CaCO3.
I didn't furnish the exact equation but it doesn't change anything in my answer.
CaCO3 + 2HCl ==> CaCl2 + CO2 + H2O
20ml solution (3.65/1000ml)(1mol hcl/36.4527gHcl)(1mol CaCo3/2molHCl) (100.0872 g CaCo3/1 mol CaCo3)= 0.1002g CaCo3