What is the molarity of an h3po4 solution if 15.0 ml is completely neutralized by 38.5 ml of 0.150m naoh?

The molarity of H3PO4 solution if 15.0 ml is completely neutralized by 38.5 ml of 0.15m naoh is calculated as follows

find moles of NaOH used = molarity x volume

= 38.5 x 0.15 = 5.775 moles

write the reacting equation

3NaOH + H3PO4 = Na3PO4 + 3H2O

from the equation the reacting ratio between NaOH to H3Po4 which is 3:1 the moles of H3PO4 is therefore = 5.775/3 = 1.925 moles

molarity of H3PO4 is therefore = moles / volume

= 1.925/15 = 0.128 M