Question

What is the theoretical and percent yield of the solid product if a solution containing 33.40 grams of sodium phosphate produced 19.60 g of AlPO₄(s) when reacted with 33.40 g aluminum chloride in solution? The chemical formula MAY be unbalanced!

(Na = 22.99 amu, P = 30.97 amu, O = 16.00 amu, Al = 26.98 amu, Cl = 35.45 amu)

Na₃PO₄(aq) + AlCl₃(aq) → NaCl(aq) + AlPO₄(s)

Answer 1

Balanced equation:
Na₃PO₄(aq) + AlCl₃(aq) = 3 NaCl(aq) + AlPO₄(s).

33.40 g aluminum chloride  = 33.4 / 133.3 = 0.250 Moles

33.40 grams of sodium phosphate = 33.4 / 163.9 = 0.2037 Moles

Both reactants needs one equivalent

Hence  sodium phosphate is limiting reagent

0.2037 Moles of sodium phosphate will produce the same mole (0.2037 Moles) of AlPO4

0.2037 Moles of AlPO4 = 0.2037 x 121.95 = 24.84 gm

The theoretical Yield = 24.84 gm

The percent yield  = 19.6 x 100 / 24.84 = 78.9 %