How many ML of a 0.10 M NaOH solution are needed to neutralize 15 Ml of a 0.20 M H3PO4 solution?

Question

How many ML of a 0.10 M NaOH solution are needed to neutralize 15 ml of a 0.20 M H3PO4 solution?.

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Answer 1

3NaOH + H₃PO₄ ==> Na₃PO₄ + 3H₂O ... balanced equation

NOTE it takes THREE moles NaOH to neutralize ONE mole H3PO4

Moles H₃PO₄ present = 15 ml x 1 L/1000 ml x 0.20 mol/L = 0.003 moles

Moles NaOH needed = 3 x 0.003 = 0.009 moles NaOH

Volume of 0.1 M NaOH needed:

(x L)(0.1 mol/L) = 0.009 moles

x = 0.09 L = 90 mls