How do I solved this AP Chemistry problem on AgBr?

Question

Silver ion and bromine ion precipitate into AgBr (s). The Ag+ concentration is about 0.065M. If the Br- concentration remains 1.0×10^17M, what will be the remaining concentration of Ag+ when the precipitation stops.

 

Ksp=7.7×10^13

Answer 1

John F. -- sometime you'll have to deal with the difference between 10^-13 and 10^13, and between 10^-17 and 10^17. They're NOT the same. The way you've stated the problem, it's impossible to tell what's going on. There would be no logical reason for the Br- level to "stay" at 10^-7M (if that's what you meant). If that's a final level, so be it; then solve as [Ag(+)][Br(-)]=Ksp.