A 25.00 mL sample of H₃PO₄ solution is neutralized by exactly 54.93 mL of 0.04345 M Ca(OH)₂. What is the molarity of the H₃PO₄ solution?

Question

Quizplus · Accepted Answer

The balanced chemical equation for the reaction is:2H₃PO₄ + 3Ca(OH)₂ → Ca₃(PO₄)₂ + 6H₂OFrom the stoichiometry of the balanced equation, we can see that 2 moles of H₃PO₄ react with 3 moles of Ca(OH)₂. Therefore, the number of moles of H₃PO₄ in the 25.00 mL sample is:(54.93 mL Ca(OH)₂) × (0.04345 M Ca(OH)₂) × (2 mol H₃PO₄ / 3 mol Ca(OH)₂) = 0.00300 mol H₃PO₄The molarity of the H₃PO₄ solution is therefore:(0.00300 mol H₃PO₄) / (0.02500 L solution) = 0.1200 MThe correct answer is therefore A) 0.0636 M.

A 2500 ML Sample of H3PO4 Solution Is Neutralized by Exactly

A 2500 ML Sample of H₃PO₄ Solution Is Neutralized by Exactly