Answer to Question #87321 in Inorganic Chemistry for Fadiena

Question

Assuming that the sodium sulphate sample is 100% pure, calculate the volume of 0.25 M BaCL2 required to precipitate all the sulphate in it. (as in step 4 in the precipitation stage in the experiment). What is the formula use for this question ? thank you.

Answer 1

 1 mol     X mol

Na₂SO₄ +BaCl₂ = BaSO₄↓ + 2NaCl

 1 mol     1 mol

n(Na₂SO₄) = 1 mol = 142 g/mol.

n(BaCl₂) = X = 1 mol.

V(BaCl₂) = n(BaCl₂) / C(BaCl₂) = 1 mol / 0.25 M = 4 L.