Question #0e38d

1 Answer
May 15, 2015

The solubility product constant for this salt will be 1.22103.

When dissolved in water, your salt will dissociate into cations and anions according to the following equilibrium

AB3(s)A3+(aq)+3B(aq)

Since you're dealing with a 1.00-L solution, the molar solubility of your salt will be

C=nV=0.0820 moles1.00 L=0.0820 mol/L

Take a look at the mole ratio that exists between the species involved in the equilibrium. You have 1 mole of AB3 dissociating to produce 1 mole of A3+ and 3 moles of B.

You can use an ICE table to determine the value of the Ksp.

AB3(s)A3+(aq)+B(aq)
I.....................0..............0
C..................(+x)...........(+3x)
E....................x...............3x

By definition, Ksp will be

ksp=[A3+][B]3=x(3x)3=27x4

But x is actually the molar solubility of the salt, 0.0820 mol/L, which means that the value of the solubility product constant will be

Ksp=27(0.0820)4=1.22103