step 1;write the equation for reaction
the equation for reaction is as follows
NaOH + H3PO4 ---> Na2 PO4 + H2o
then calculate the moles of H3PO4 used
that is 34.55 x1.500/1000= 0.052 moles
by use of mole ratio between NaOH to H3Po4 which is 1:1 the moles of NaOh= 0.052 moles
volume of NaOh is= moles of NaOH/ molarity
that is 0.052 /1.420=0.03662 L
in Ml = 0.03662 x1000=36.62 Ml
