Stoichiometry Problem

Question

2.   If 0.380 mol of sodium  phosphate is allowed to react with an excess of  sulfuric  acid, how many moles of phosphoric acid  could  be  formed?

                                      Na3PO4     +      H2SO4           H3PO4    +     Na2SO4

Answer 1

First balance the reaction to get correct mole ratios: 2 Na₃PO₄ + 3 H₂SO₄ --> 2 H₃PO₄ + 3 Na₂SO₄.

Now we see that the mole ratio of H₃PO₄ to Na₃PO₄ is 2:2, therefore 0.380 moles of H₃PO₄ are produced.