You need to start with a balanced equation.
So balance:
Na3PO4 + HCl = H3PO4 + NaCl
Sodium phosphate, Na3PO4, reacts with HCl to form H3PO4 and NaCl. How many liters of 0.1 M HCl are required to react with 0.1 mole of sodium phosphate?
2 answers
Na3PO4 + 3HCL = H3PO4 +3NaCl