What is the molar concentration of a phosphoric acid (h3po4) solution if 55.5 ml of the solution requires 35.5 ml of. 150 m naoh to completely react with the phosphoric acid?

The molar concentration of H3PO4 solution is calculated as below

find the moles of NaOH reacted = molarity x volume

= 35.5 x0.150 = 5.325 moles

write a balanced reacting equation

=NaOH + 3 H3PO4 = Na3PO4 + 3H2O

by use of reacting ratio between NaOH to H3PO4 which is 1:3 the moles of H3Po4 is therefore

= 5.325moles/3 = 1.775 moles

molar concentration is therefore of H3PO4 = moles / volume

=1.775/55.3 = 0.0320 M of H3PO4