Answer to Question #345837 in General Chemistry for Jonalyn

Question

1.)calculate the volume of 0.400M H3PO4 needed to react with 200.0mL of 0.200 M NaOH

____H3PO4 (aq) +___NaOH(aq) -____Na3PO4(aq) +___H2O(l)

Answer 1

Solution:

Balanced chemical equation:

H₃PO₄(aq) + 3NaOH(aq) → Na₃PO₄(aq) + 3H₂O(l)

According to stoichiometry:

Moles of H₃PO₄ = Moles of NaOH / 3

3 × Molarity of H₃PO₄ × Volume of H₃PO₄ = Molarity of NaOH × Volume of NaOH

Therefore,

Volume of H₃PO₄ = (Molarity of NaOH × Volume of NaOH) / (3 × Molarity of H₃PO₄)

Volume of H₃PO₄ = (0.200 M × 200.0 mL) / (3 × 0.400 M) = 33.33 mL

Volume of H₃PO₄ = 33.33 mL

Answer:  The volume of H₃PO₄ is 33.33 mL