Question

What is the concentration (in molarity) of a hydrochloric acid solution, HCl, if 25.0 ml of a 0.100 M sodium hydroxide solution, NaOH, was required to neutralize 35.0 ml of the HCl solution during a titration?

Answer 1

To solve this problem, we can use the concept of stoichiometry and the balanced chemical equation for the reaction between hydrochloric acid  HCl  and sodium hydroxide  NaOH :HCl aq  + NaOH aq   NaCl aq  + H2O l From the balanced equation, we can see that the mole ratio between HCl and NaOH is 1:1.First, we need to find the moles of NaOH used in the reaction:moles of NaOH = volume of NaOH  L   concentration of NaOH  M moles of NaOH = 0.025 L  0.100 Mmoles of NaOH = 0.00250 molSince the mole ratio between HCl and NaOH is 1:1, the moles of HCl in the reaction are equal to the moles of NaOH:moles of HCl = 0.00250 molNow, we can find the concentration of HCl using the volume of the HCl solution:concentration of HCl  M  = moles of HCl / volume of HCl  L concentration of HCl  M  = 0.00250 mol / 0.035 Lconcentration of HCl  M  = 0.0714 MTherefore, the concentration of the hydrochloric acid solution is approximately 0.0714 M.