Question

In a titration, the endpoint of a neutralization reaction was reached when 37.6 milliliters of an HCl solution was added to 17.3 milliliters of a 0.250 M NaOH solution. What was the molarity of the HCl solution?

Answer 1

the balanced equation for the reaction is as follows
NaOH + HCl --> NaCl + H₂O
stoichiometry of NaOH to HCl is 1:1
number of NaOH moles reacted - 0.250 mol/L x 0.0173 L = 0.00433 mol
number of HCl moles reacted - 0.00433 mol
there are 0.00433 mol in 37.6 mL
therefore in 1000 mL - 0.00433 mol / 37.6 mL x 1000 mL = 0.115 mol
molarity of HCl is 0.115 M