Question

What is the concentration of barium ions in a saturated solution of barium sulfate?

K_sp(BaSO₄) = (2.373x10^-8)

Answer 1

The solubility expression for BaSO₄ is as follows:

BaSO₄(s) Ba²⁺(aq) + SO₄^2-

Draw an ICE chart for the equilibrium as follows:

	BaSO4(s)	Ba2+(aq)	SO42-
I(M)	-	0	0
C(M)	-	+S	+S
E(M)	-	S	S

K_sp expression for the above equilibrium is as follows:

K_sp = [Ba²⁺] [SO₄^2-]

As per the ICE chart,

K_sp = [S] [S]

K_sp = [S]²

2.373 x 10^-8 = [S]²

S = 1.54 x 10^-4 mol/L

As per the ICE chart,

[Ba²⁺] = [SO₄^2-] = 1.54 x 10^-4 mol/L

Hence, concentration of barium ions in the saturated solution of barium sulfate is 1.54 x 10^-4 mol/L.