Sodium sulfate is slowly added to a solution containing 0.0500 M Ca^2+ (aq) and 0.0390 M Ag^+ (aq). What will be the concentration of Ca^2+ (aq) when Ag2SO4(s) begins to precipitate?
What percentage of the Ca^2+ (aq) can be separated from the Ag^+ (aq) by selective precipitation?
You need to provide Ksp of each. I have those but all texts don't agree. I may use different ones than you have.
Just take the coeffficients to be the divisors of the denominator. Then take the reciprocal, divide by the lattice energy of the molar solubility, and you've got your solution!
To find the concentration of Ca^2+ (aq) when Ag2SO4(s) begins to precipitate, we need to determine the solubility product constant (Ksp) of Ag2SO4 and compare it to the ion product of Ca^2+ and SO4^2-.
1. Write the balanced chemical equation for the reaction:
2Ag^+(aq) + SO4^2-(aq) -> Ag2SO4(s)
2. Write the Ksp expression for Ag2SO4:
Ksp = [Ag^+]^2 * [SO4^2-]
3. Calculate the ion product (IP) using the initial concentrations of Ca^2+ and Ag^+:
IP = [Ca^2+] * [SO4^2-] = 0.0500 M * 0.0390 M = 0.00195
4. Determine the Ksp value of Ag2SO4 from reliable sources or references. Let's assume the Ksp value of Ag2SO4 is 1.2 x 10^-5.
5. Compare the ion product (IP) to the Ksp value (Ksp) to determine if precipitation will occur:
If IP > Ksp, precipitation occurs.
If IP < Ksp, no precipitation occurs.
In this case, IP (0.00195) is greater than Ksp (1.2 x 10^-5), indicating that Ag2SO4 will begin to precipitate.
To find the percentage of Ca^2+ that can be separated from Ag^+ by selective precipitation, we need to determine the initial concentration of Ca^2+ and the concentration of Ca^2+ after Ag2SO4 has precipitated.
1. Calculate the amount of Ag^+ that reacts with the amount of SO4^2- to form Ag2SO4:
Since the balanced chemical equation shows a 1:1 molar ratio between Ag^+ and SO4^2-, the amount of Ag^+ and SO4^2- that react will be equal.
2. Calculate the moles of Ag2SO4 formed using the known amount of Ag^+ and the molar mass of Ag2SO4:
Moles of Ag2SO4 = moles of Ag^+ = Molarity of Ag^+ * volume of solution in liters
3. Calculate the moles of Ca^2+ precipitated by stoichiometry:
From the balanced chemical equation, the stoichiometry is 1:1 between Ag2SO4 and Ca^2+. Therefore, the moles of Ca^2+ precipitated will be equal to the moles of Ag2SO4 formed.
4. Calculate the concentration of Ca^2+ after precipitation:
Concentration of Ca^2+ after precipitation = (initial concentration of Ca^2+ - moles of Ca^2+ precipitated) / volume of solution in liters
5. Calculate the percentage of Ca^2+ that has been separated from Ag^+:
Percentage = ([initial concentration of Ca^2+ - concentration of Ca^2+ after precipitation] / initial concentration of Ca^2+) * 100%