Question

14.6 mL of hydrochloric acid is completely neutralized by 25.0 mL of 1.40 M sodium hydroxide, what was the hydrochloric acid mass percent (m/m) before the titration? (Density of hydrochloric acid is 1.02 g/cm3)

Answer 1

First determine the molarity of the HCl.
mols NaOH = M x L = ?
mols HCl = mols NaOH
M HCl = mols HCl/L solution. You know mols and L(convert mL to L), solve for M.

M HCl means mols/L solution
Convert mols HCl to grams HCl. mols = grams/molar mass. You know molar mass and mols, solve for grams. That gives you grams HCl/1000 mL solution. Use density to convert 1000 mL to grams solution and g HCl/g solution will give
you g HCl/1020 g solution. That x 100 gives you % HCl m/m
I think the answer is approx 10% m/m