Question

The solubility of BaSO4 is measured and found to be 2.35x10-3 g/L. Use this information to calculate a Ks value for barium sulfate. Ksp = Submit Answer Retry Entire Group 9 more group attempts remaining

Answer 1

Molar mass of BaSO4,

MM = 1*MM(Ba) + 1*MM(S) + 4*MM(O)

= 1*137.3 + 1*32.07 + 4*16.0

= 233.37 g/mol

Molar mass of BaSO4= 233.37 g/mol

s = 2.35*10^-3 g/L

To covert it to mol/L, divide it by molar mass

s = 2.35*10^-3 g/L / 233.37 g/mol

s = 1.007*10^-5 mol/L

At equilibrium:

BaSO4 <----> Ba2+ + SO42-

   s s

Ksp = [Ba2+][SO42-]

Ksp = (s)*(s)

Ksp = 1(s)^2

Ksp = 1(1.007*10^-5)^2

Ksp = 1.014*10^-10

Answer: 1.01*10^-10