Calculate the concentration of the HCl solution.

Question

By titration, it is found that 85.5 mL of 0.177 M NaOH(aq) is needed to neutralize 25.0mL of HCl(aq). Calculate the concentration of the HCl solution.

[HCl]=?M

Answer 1

HCl + NaOH ==> NaCl + H2O ... balanced neutralization reaction

moles NaOH used = 85.5 ml x 1 L / 1000 ml x 0.177 mol / L = 0.0151 mols

moles HCl present = 0.0151 mols NaOH x 1 mol HCl / 1 mol NaOH = 0.0151 mols HCl

Concentration HCl = 0.0151 mols / 25.0 ml x 1000 ml / L = 0.604 M