A solution of 0.314M KOH is used to neutralize 10.0mL H3PO4 solution.

Question

H3PO4(aq) + 3KOH(aq) → K3PO4(aq) + 3H2O(lIf 29.3mL KOH solution is required to reach the endpoint, what is the molarity of the H3PO4 solution?)

Answer 1

mols KOH = M x L = ?
Using the coefficients in the balanced equation, convert mols KOH to mols H3PO4.
Then M H3PO4 = mols H3PO4/L H3PO4.