A solution is 0.1 M in each KCl, KBr and K2CrO4. To this solution solid AgNO3 is gradually added. Assume no change in the volume of the solution.
Given: Ksp(AgCl)=1.7×10−10
Ksp(AgBr)=5×10−13
and Ksp(Ag2CrO4)=1.9×10−12
The concentration of [Ag+] required to start the precipitation of AgBr is:
[Ag+] to start the precipitation of Br−=Ksp(AgBr)[Br−]=5×10−130.1=5×10−12 M