If BaCl2 is added in excess, what’s the theoretical yield of Ba2SO4 if (4.67•10^-4) moles of Na2SO4 are present in the water sample?

Question

BaCl₂ + Na₂SO₄ = 2 NaCl + BaSO4

Answer 1

Since we have an excess of BaCl₂, we can convert the moles of Na₂SO₄ to moles of BaSO₄. Because there is less Na₂SO_4, when it runs out, there will be no more sulfate ions to form BaSO₄ molecules. Looking at the coefficients in the formula, we can see they have a one to one ratio, meaning since we have 4.67 x 10^-4 moles of Na₂SO₄ we will have 4.67 x 10^-4 moles of BaSO₄. If you need grams, then multiply this value by the molar mass of BaSO₄ which is 233.38 g/mole.