At a certain temperature, the solubility of strontium arsenate, Sr3(AsO4)2, is 0.0510 g/L. What is the Ksp of this salt at this temperature?
.......Sr3(AsO4)2 ==> 3Sr^2+ + 2AsO4^3-
solubility...x........3x........2x
x = 0.0510g/L. Convert to mol/L, then substitute into Ksp expression.
To find the solubility product constant (Ksp) of strontium arsenate (Sr3(AsO4)2), you need the equation of its dissolution in water:
Sr3(AsO4)2(s) ⇌ 3Sr2+(aq) + 2 AsO42-(aq)
Based on this equation, you can establish the equilibrium expression for the solubility product:
Ksp = [Sr2+]^3 × [AsO42-]^2
Since the concentration of Sr3(AsO4)2 is given in g/L, you'll need to convert it into molar concentration (mol/L). To do this, you'll need the molar mass of Sr3(AsO4)2 and the conversion:
Molar mass of Sr3(AsO4)2 = 1032.24 g/mol
Molar concentration (mol/L) = (given concentration (g/L)) / molar mass (g/mol)
Let's calculate the molar concentration first:
Molar concentration = 0.0510 g/L / 1032.24 g/mol
Molar concentration = 4.94 × 10^-5 mol/L (approximately)
Now, substitute this molar concentration into the Ksp expression:
Ksp = [Sr2+]^3 × [AsO42-]^2
Ksp = (4.94 × 10^-5)^3 × (4.94 × 10^-5)^2
Ksp = 0.00000000001891 (approximately)
Therefore, the Ksp of strontium arsenate at this temperature is approximately 1.891 × 10^-11.
To determine the Ksp (solubility product constant) of strontium arsenate (Sr3(AsO4)2) at a certain temperature, we need to use the given solubility and the balanced chemical equation for the dissolution of the salt.
The solubility product constant (Ksp) represents the equilibrium constant for the dissolution of a chemical compound in water. In the case of the compound Sr3(AsO4)2, it dissociates into strontium ions (Sr2+) and arsenate ions (AsO42-).
The balanced chemical equation for the dissolution of strontium arsenate is:
Sr3(AsO4)2(s) -> 3Sr2+(aq) + 2AsO42-(aq)
Based on the solubility given (0.0510 g/L), we can find the molar solubility (in mol/L) of Sr3(AsO4)2.
First, we need to calculate the molar mass of Sr3(AsO4)2:
Sr = 87.62 g/mol
As = 74.92 g/mol
O = 16.00 g/mol
Molar mass of Sr3(AsO4)2 = (87.62 * 3) + (74.92 * 2) + (16.00 * 8) = 621.07 g/mol
Next, we can calculate the molar solubility (in mol/L) using the solubility given:
Molar solubility = (0.0510 g/L) / (621.07 g/mol)
Now, we can write the expression for Ksp using the molar solubility (S):
Ksp = [Sr2+]^3 * [AsO42-]^2
Since there is a 3:2 stoichiometric ratio between Sr2+ and AsO42- in the balanced equation, we substitute (3S)^3 for [Sr2+]^3 and (2S)^2 for [AsO42-]^2:
Ksp = (3S)^3 * (2S)^2 = 108S^5
Finally, we substitute the molar solubility value obtained earlier into the expression for Ksp:
Ksp = 108 * (molar solubility)^5