Question

A student completes a titration by adding 12.0 milliliters of NaOH(aq) of unknown concentration to 16.0 milliliters of 0.15 M HCl(aq). What is the molar concentration of the NaOH(aq)?

Answer 1

Запишем уравнение реакции:
NaOH + HCl = NaCl + H2O
C NaOH*V NaOH = C HCl*V HCl
где: C NaOH и C HCl - молярные концентрации гидроксида натрия и хлорида водорода соответственно, моль/л; V NaOH и V HCl - объемы растворов гидроксида натрия и соляной кислоты соответственно, л.
Молярная концентрация NaOH равна:
C NaOH*V = C HCl*V HCl/V NaOH = 0,016*0,15/0,012 = 0,2 моль/л

We write the reaction equation:
NaOH + HCl = NaCl + H2O
C NaOH * V NaOH = C HCl * V HCl
where: C NaOH and C HCl - molar concentration of sodium hydroxide and hydrogen chloride, respectively, mol / l; V NaOH and V HCl - volumes of the solutions of sodium hydroxide and hydrochloric acid, respectively, l.
Molar concentration of NaOH is:
C NaOH * V = C HCl * V HCl / V NaOH = 0,016 * 0,15 / 0,012 = 0,2 mol / l