When 50.0 mL of a 2.0 × 10-4 M Ag2CrO4 solution was added to 50.0 mL of a Na2CrO4 solution a ppt formed (Ag2Cro4). What was the initial concentration of this Na2CrO4 solution?
Ksp Ag2CrO4 = 1.1 × 10-12
Given A2 (aq) + B(aq) -> AB(s)
Ksp = [A]n
The Attempt at a Solution
I tried using the "ICE" Table, but it didn't help:
Ag2CrO -> 2Ag + CrO4
I 2.0x10-4 2.0x10-4 ?
C +x(?) -2x(?) -x(?)
E 2.0x10-4(unchanged) 2.75x10-5
I found [CrO4] at eqb using Ksp equation. (2.75x10-5M)
The initial [CrO4] was the [CrO4] from Ag2CrO4 plus Na2CrO4, right?
but why is it that [CrO4] at equilibrium is smaller than that of the initial [CrO4] in the initial Ag2CrO4 concentration?
Can anyone solve this problem???
Explanation would be nice :)