What volume of a 0.332 M perchloric acid solution is required to neutralize 11.5 mL of a 0.173 M barium hydroxide solution?

2HClO₄ + Ba(OH)₂ → BaClO₄ + 2H₂O
Mole ratio HClO₄ : Ba(OH)₂ = 2 : 1

No. of moles of Ba(OH)₂ reacted = (0.173 mmol/mL) × (11.5 mL) = 1.99 mmol
No. of moles of HClO₄ required = (1.99 mmol) × 2 = 3.98 mmol
Volume of HClO₄ solution required = (3.98 mmol) / (0.332 mmol/mL) = 12.0 mL