Question

The mass of barium sulfite that is dissolved in 250 mL of a saturated solution is ___ grams.

Answer 1

Ksp of BaSO4 is 1.1x10^-10

The ionization of BaSO4 in water is given by

BaSO4 (s) <=====> Ba^2+(aq) + SO4^2-(aq)

Ksp = [Ba^2+][SO4^2-] = 1.1x10^-10

The solubility of Ba^2+ and SO4^2- is S mol/L in its saturated solution,

Ksp = S^2 = 1.1x10^-10

S = sqrt(1.1*10^-10) = 1.05*10^-5 M

Solubility of BaSO4 in g/L is = molar mass*S

= 233*(1.05*10^-5) = 2.44x10^-3 g/L

Solubility in 250ml is (2.44x10^-3*250) /1000 = 6.11x10^-4 g

The mass of BaSO4 in 250ml of saturated solution is 6.11x10^-4 g