Question

In a titration, 25.00mL of 0.10mol L-1 sodium hydroxide solution was required to neutralize 12.5 mL of hydrochloric acid. Calculate the concentration of hydrochloric acid.

Answer 1

0.0025mol   X mol

    NaOH    +   HCl = NaCl + H₂O

    1 mol       1 mol

n(NaOH) = C(NaOH) × V(NaOH) = 0.10 mol L^-1 × 0.025L = 0.0025 mol.

n(HCl) = X mol = 0.0025 mol.

C(HCl) = n(HCl) / V(HCl) = 0.0025 mol / 0.0125 L = 0.20 mol L^-1.