Which of the following mixtures will result in the formation of a precipitate of #Ag_2SO_4#?

We have the following four solutions:
A #[Ag^+] =# 1e-4
B #[Ag^+] =# 3e-8
C #[SO_4^-2] =# 6e-3
D #[SO_4^-2] =# 5e-7

#K_sp# for #Ag_2SO_4 =# 2.93e-13

A + C
A + D
A + B
B + C
B + D

1 Answer
Dec 10, 2017

Well, what is the ion product #Q# in each case....?

Explanation:

We address the equilibrium...

#2Ag^+ +SO_4^(2-) rarr Ag_2SO_4(s)darr#

Now #K_"sp"=[Ag^+]^2[SO_4^(2-)]#...and this is simply an equilibrium expression. And all we have to do is calculate the ion product....#Q=[Ag^+]^2[SO_4^(2-)]#.

If #[Ag^+]^2[SO_4^(2-)]>K_"sp"# then precipitation will occur...

If #[Ag^+]^2[SO_4^(2-)]<=K_"sp"# then the sulfate will remain in solution. I will do the first and then you are on your own....

We try #A.+C.#, #[Ag^+]=1xx10^-4*mol*L^-1#; #[SO_4^(2-)]=6xx10^-3*mol*L^-1#.

The ion product, #Q=(1xx10^-4)^2xx(6xx10^-3)=6.0xx10^-11#.

Now #Q">>"K_"sp"=2.93xx10^-13#...and so precipitation will occur.

And now you use the same procedure on all the other examples. You could post them here....