Question

N aqueous solution of sodium hydroxide is standardized by titration with a 0.154 m solution of hydrochloric acid. if 17.5 ml of base are required to neutralize 17.6 ml of the acid, what is the molarity of the sodium hydroxide solution?

Answer 1

the balanced equation for the above reaction is as follows;
NaOH + HCl --> NaCl + H₂O
stoichiometry of NaOH to HCl is 1:1
Number of HCl moles reacted - 0.154 mol/L x 0.0176 L = 0.00271 mol
the number of NaOH moles reacted = number of HCl moles reacted
number of NaOH moles reacted - 0.00271 mol
number of NaOH moles in 17.5 mL - 0.00271 mol
therefore NaOH moles in 1000 mL - 0.00271 mol / 17.5 mL x 1000 mL
molarity of NaOH - 0.155 M