A 5.00 mL sample of an aqueous solution of H3PO4 requires 43.2mL of 0.285M NaOH to convert all of the H3PO4 to Na2HPO4. The other product of the reaction is water.

Question

A 5.00 mL sample of an aqueous solution of H3PO4 requires 43.2mL of 0.285M NaOH to convert all of the H3PO4 to Na2HPO4. The other product of the reaction is water.
Calculate the molarity of the H3PO4 solution.

DrBob222 · Answer

H3PO4 + NaOH ==> NaH2PO4 + H2O mols NaOH = M x L = ? 1 mol NaOH = 1 mol H3PO4 M H3PO4 = mols H3PO4/L H3PO4.