Question

if you dissolve .02 mol of barium hydroxide in enough water to make 250 ml of solution, what volume of .1 M hydrochloric acid is required to react completely with the barium hydroxide

Answer 1

The balanced equation for this reaction is

Ba(OH)₂ + 2HCl -----> BaCl₂ + 2H₂O

0.02 mol barium hydroxide is 3.426 g of barium hydroxide.

for complete reaction this will require 2 equivalents of HCl or 0.04 moles. Molecular weight of HCl is 36.4 g/mole. So for 0.04 moles we will need 1.45 g of HCl.

0.1 M HCl contains 0.1 moles of HCl /Litre or 3.64g of HCl in 1 Litre so 1.45 g is present in 398 mL of the 0.1M HCl solution.

So we will need 398 ML of 0.1M HCl to completely react with 0.02mol of Barium hydroxide dissolev in 250 ml.