Question

A 75.0g sample of liquid contains 17.5% by mass of H3PO4 (molar mass = 98.0g/mol). If
215.0mL of Ba(OH)2 is needed to completely neutralize the acid, determine the concentration
of the Ba(OH)2 solution used

Answer 1

assuming no other acid is in the H3PO4 mix, then
a) the equation
2H3PO4 + 3Ba(OH)2>>3H2O+Ba3(PO3)2

titration equation:
nb*Ma*Va=na*Mb*Vb
nb*molesacid=na*molesbase
3*75*.175/98=2*Molaritybase*.215
solve for molarity of base

Answer 2

0.00092mol/L

Answer 3

0.927 mol/L

Answer 4

0.937