Posted by chem question on .
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.
Thanks, I got it!
Why do you have to square Ag after you got the Molarity?
Yes square molarity