Determine the volume of 2.3 M H3PO4 that can completely react with?

Question

340 mLs of a 5.1 M solution of NaOH according to the reaction:
3 NaOH + H3PO4 --> Na3PO4 + 3 H2O

stuck on a homework problem..pls help!

Answer 1

you want three moles of NaOH for each mole of H3PO4

moles NaOH= .340*5.1
moles H3PO4= 1/3 * .340*5.1
volumeof H3PO4= molesH3PO4/2.3 in liters.