#24

At a certain temperature, the solubility of strontium arsenate, Sr3(AsO4)2, is 0.0660 g/L. What is the Ksp of this salt at this temperature?

See you post on AB3.

To find the Ksp (solubility product constant) of strontium arsenate (Sr3(AsO4)2), we need to use the given solubility and the balanced equation for the dissolution of the salt.

The balanced equation is:
Sr3(AsO4)2(s) ⇌ 3Sr2+(aq) + 2AsO4^3-(aq)

The solubility of strontium arsenate is given as 0.0660 g/L, which represents the concentration of the ions in the saturated solution.

Now, let's assume the solubility of Sr3(AsO4)2(s) is "s". Since three Sr2+ ions are produced for every Sr3(AsO4)2 molecule that dissolves, the concentration of Sr2+ ions in the saturated solution is 3s. Likewise, since the ratio of AsO4^3- ions to Sr3(AsO4)2 molecules is 2:1, the concentration of AsO4^3- ions in the saturated solution is 2s.

Using these concentration expressions, we can write the expression for the Ksp of strontium arsenate:

Ksp = [Sr2+]^3 * [AsO4^3-]^2

Substituting the concentrations, we have:

Ksp = (3s)^3 * (2s)^2
= 54s^5

To find the value of s, we can use the given solubility. Since 0.0660 g of Sr3(AsO4)2 dissolves in 1 L of solution, the molar solubility can be calculated by dividing the mass by the molar mass:

molar solubility of Sr3(AsO4)2 = 0.0660 g / (3 * atomic mass of Sr + 2 * atomic mass of As + 8 * atomic mass of O) g/mol

By substituting the atomic masses of Sr, As, and O, and evaluating the expression, we can obtain the molar solubility.

Once you have the molar solubility, substitute the value of s into the equation for Ksp we derived earlier to find the solubility product constant (Ksp) of strontium arsenate at the given temperature.