Question

How many milliliters of 0.666 M HBr are needed to titrate each of the following solutions to the equivalence point?




(a) 75.4 mL of 0.333 M LiOH

____________ mL



(b) 21.8 mL of 0.666 M KOH

_____________mL



(c) 102.0 mL of a solution that contains 34.1 g of RbOH per liter

___________mL

Answer 1

(a) 75.4 mL of 0.333 M LiOH

mmol of LiOH = MV = 75.4*0.333 = 25.1082 mmol of LiOH

for neutralization

mmol of acid = mmol of base = 25.1082

Volume of acid = mmol/M = (25.1082)/0.666 = 37.7 mL of acid

(b) 21.8 mL of 0.666 M KOH

mmol of KOH = MV = 21.8 *0.666 = 14.5188 mmol of KOH

for neutralization

mmol of acid = mmol of base = 14.5188

Volume of acid = mmol/M = (14.5188)/0.666 = 21.8 mL of acid

(c) 102.0 mL of a solution that contains 34.1 g of RbOH per liter

mol of base = mass/MW = 34.1/102.475 = 0.332764mol of RbOH per liter

mol = MV= 102*0.332764 = 33.941928 mmol of base

mmol of acid = 33.941928

Vacid = mmol/M = 33.941928/0.666 = 50.9638mL