The molarity of 15.0 mL HCl solution that requires 18.40 mL of 0.10 M NaOH to reach endpoint will be 0.12 M
From the equation of the reaction:
HCl + NaOH -----------. NaCl + H2O
Mole ratio of acid and base = 1:1
Using the equation: MaVa/MbVb = 1/1
where Ma = molarity of acid, Va = volume of acid, Mb = molarity of base, and Vb = volume of base.
Ma = MbVb/Va
= 0.1 x 18.40/15.0
= 0.12 M
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