Answer to Question #85078 in Chemistry for Sierra

Question

For the following chemical reaction, what mass of phosphoric acid, H3PO4, in grams will be needed to produce 1.71 mol of water, H2O?

3KOH+H3PO4⟶K3PO4+3H2O

Answer 1

Chemical reaction:

3KOH + H₃PO₄ ⟶ K₃PO₄ + 3H₂O

Mr (H₃PO₄)= 3(Ar(H)) + Ar(P) + 4(Ar(O))= 3 × 1+ 31 + 4 × 16 = 98 g/mol

Mr = M = 98 mol

m(H₃PO₄) = x = (98 mol × 1.71 mol) / (3 mol) = 55,86 g.

Answer: Mass of phosphoric acid, H₃PO₄ is 55,86 g.