For which of the following mixtures will Ag2SO4(s) (Ksp=1.20E^-5)precipitate?
More than one answer can be selected.
a.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.20 M AgNO3(aq)
b.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.30 M AgNO3(aq)
c.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.40 M AgNO3(aq)
d.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.50 M AgNO3(aq)
Calculate (Ag^+) and (SO4^2-), substitute into Ksp expression. That is Qsp.
If Qsp > Ksp a ppt will occur. If Qsp < Ksp, no ppt will occur.
For example, a)
(SO4^2-) = 150.0 x 0.10/155.0)= 0.0968M
(Ag^+) = 5.0 x 0.2/155.0 = 0.00645M
(0.00645)^2(0.0968) = 4.03E-6 which is smaller than Ksp = 1.20E-5; therefore, no ppt of Ag2SO4 will occur.
E-6
Thanks, I got it!
Why do you have to square Ag after you got the Molarity?
-(0.00645)^2(0.0968)=4.03E-6
Yes square molarity
To determine whether Ag2SO4(s) will precipitate in each mixture, we need to calculate the Qsp (the reaction quotient) and compare it to the Ksp (solubility product constant) for Ag2SO4.
The balanced equation for the precipitation reaction is:
AgNO3(aq) + Na2SO4(aq) → Ag2SO4(s) + 2NaNO3(aq)
The Qsp can be calculated using the concentrations of the ions in the mixtures. Here's how you can calculate Qsp for each mixture:
a.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.20 M AgNO3(aq):
- The concentration of Na2SO4(aq) is 0.10 M.
- The concentration of AgNO3(aq) is 0.20 M.
- Qsp = [Ag+]^2 * [SO4 2-] = (0.20 M)^2 * (0.10 M) = 0.004 M^3
b.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.30 M AgNO3(aq):
- The concentration of Na2SO4(aq) is 0.10 M.
- The concentration of AgNO3(aq) is 0.30 M.
- Qsp = [Ag+]^2 * [SO4 2-] = (0.30 M)^2 * (0.10 M) = 0.009 M^3
c.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.40 M AgNO3(aq):
- The concentration of Na2SO4(aq) is 0.10 M.
- The concentration of AgNO3(aq) is 0.40 M.
- Qsp = [Ag+]^2 * [SO4 2-] = (0.40 M)^2 * (0.10 M) = 0.016 M^3
d.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.50 M AgNO3(aq):
- The concentration of Na2SO4(aq) is 0.10 M.
- The concentration of AgNO3(aq) is 0.50 M.
- Qsp = [Ag+]^2 * [SO4 2-] = (0.50 M)^2 * (0.10 M) = 0.025 M^3
Now, we need to compare the Qsp values to the Ksp value of Ag2SO4 (Ksp = 1.20E^-5):
a.) Qsp = 0.004 M^3 < Ksp - Ag2SO4 will not precipitate.
b.) Qsp = 0.009 M^3 < Ksp - Ag2SO4 will not precipitate.
c.) Qsp = 0.016 M^3 > Ksp - Ag2SO4 will precipitate.
d.) Qsp = 0.025 M^3 > Ksp - Ag2SO4 will precipitate.
Based on the comparison of Qsp to Ksp, Ag2SO4 will precipitate in mixtures (c) and (d). Therefore, the correct answer is:
c.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.40 M AgNO3(aq)
d.) 150.0 mL of 0.10 M Na2SO4(aq) and 5.0 mL of 0.50 M AgNO3(aq)