What volume of 0.500 M NaOH is needed to react with 77.5 mL of 0.220 M phosphoric acid?

Question

i know the balanced equation is H3PO4 + 3 NaOH -> Na3PO4 + 3 H2O

how do i find the amt. of mL needed to react?

Answer 1

Convert the volume of H3PO4 into liters and multiply that by 0.220 to get the moles of phosphoric acid. Multiply that by 3 since 1 mole of H3PO4 reacts with 3 moles of NaOH. Finally divide the number of moles of NaOH by 0.500 to get the volume (in Liters) of NaOH.

Answer 2

1 M of phosphoric acid reacts with 3M of NaOH
77.5 mL -------------------------(3 * 77.5) = 232.5ML