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)

Theoretical yield = Blank 1 grams of solid product

Percent yield = Blank 2 %

Answer 1

Balanced chemical reaction is

Na₃PO_4(aq) + AlCl_3(aq) → 3 NaCl_(aq) + AlPO_4(s)

molar mass of Na₃PO₄ = 163.94 gm/mol

then 33.40 gm of Na₃PO₄ = 33.40 / 163.94 = 0.2037 mole

molar mass of AlCl₃ = 133.34 gm/mol

then 33.40 gm of AlCl₃ = 33.40 / 133.34 = 0.2505 mole

According to reaction Na₃PO₄ and AlCl₃ react with each other with equimolar proportional therefore to react with 0.2505 mole of AlCl₃ required Na₃PO₄ = 0.2505 mole but Na₃PO₄ given only 0.2037 mole therefore Na₃PO₄ is liniting reactant.

According to reaction 1 mole Na₃PO₄ give 1 mole AlPO₄ therefore 0.2037 mole of Na₃PO₄ give 0.2037 mole of AlPO₄.

molar mass of AlPO₄ = 121.9529 gm/mol then 0.2037 AlPO₄ = 0.2037 X 121.9529 = 24.84 gm

Theoretical yield = 24.84 gm

Percent yield = actual yield X 100 / theoretical yield = 19.60 X 100 / 24.84 = 78.9 %

Percent yield = 78.9 %