Question

In a titration, 45.0 mL of KOH is neutralized by 75.0 mL of 0.30M HBr. How much KOH is in 1.0 liter of the KOH solution ?

Answer 1

KOH + HBr ---> KBr + H2O

0,3 moles of HBr ---in-------1000ml
x moles of HBr-------in------75ml
x = 0,0225 moles of HBr

according to the reaction:  1 mole of KOH = 1 mole of HBr
so
0,0225 moles of HBr = 0,0225 moles of KOH

0,0225 mole of KOH------in-----45ml
x moles of KOH -----------in------1000ml
x = 0,5 moles of KOH

answer: 0,5 mol/dm³  KOH (molarity)