Barrons SAT Subject Test Chemistry, 13th Edition

and

Ksp = [Ba2+][SO 4 2−]

Therefore

Another Typical Problem

Finding the solubility.

If the Ksp of radium sulfate, RaSO 4 , is 4 × 10−11, calculate the solubility of the

compound in pure water. Let x = moles of RaSO 4 that dissolve per liter of water.

Then, in the saturated solution,

Let x = [Ra2+] and [SO 4 2−]. Then

Thus the solubility of RaSO 4 is 6 × 10−6 mole/liter of water, for a solution 6 ×

10 −6 M in Ra2+ and 6 × 10−6 M in SO 4 2−.

Another Typical Problem

Predicting the formation of a precipitate.
In some cases, the solubility products of solutions can be used to predict the
formation of a precipitate.

Suppose we have two solutions. One solution contains 1.00 × 10−3 mole of

silver nitrate, AgNO 3 , per liter. The other solution contains 1.00 × 10−2 mole of

sodium chloride, NaCl, per liter. If 1 liter of the AgNO 3 solution and 1 liter of the

NaCl solution are mixed to make a 2-liter mixture, will a precipitate of AgCl
form?
In the AgNO 3 solution, the concentrations are:

[Ag+] = 1.00 × 10−3 mol/L and [NO 3 −] = 1.00 × 10−3 mol/L