By titration, it is found that 95.9 mL of 0.191 M NaOH(aq) is needed to neutralize 25.0 mL of HCl(aq). Calculate the concentration of the HCl solution.

Answer 1

First, write the balanced equation for the reaction:

NaOH + HCl ==> NaCl + H2O ... balanced equation

Next, calculate moles of NaOH used in the titration:

95.9 mls x 1 L / 1000 mls x 0.191 mols / L = 0.01832 mols NaOH used

Next, find the mols HCl present (use the stoichiometry of the balanced equation)

0.01832 mols NaOH x 1 mol HCl / mol NaOH = 0.01832 mols HCl present

Finally, find the concentration of HCl (mols/L; M) by dividing the moles HCl by the volume of HCl:

concentration = moles/ liter = 0.01832 mols / 0.025 L = 0.733 mol / L = 0.733 M