chemistry
posted by anonymous .
Can Anyone Help Me With This Solubility Problem?
An aqueous solution of 1.90 M AgNO3 is slowly added from a buret to an aqueous solution of 0.0100 M Cl and 0.250 M I.
b) When the second ion begins to precipitate, what is the remaining concentration of the first ion?
Reposting this because i already know how to do the other ones. for part B, what is the setup i use to solve this? thx

Bob Pursley gave you a hint this morning. Here is another one.
Divide Ksp AgCl/Ksp AgI =
(Ag^+)(Cl^)/(Ag^+)(I^&) = (KspAgCl)/(Ksp AgI).
(Ag^+) cancels so you can get a ratio of
(Cl^)/(I^) = ??
Substitute numbers and solve for (Cl^) 
the ksp for AGCL is 1.8*10^11, and the ksp for AGI came out to 8.5*10^11. when i divided the numbers and set them equal to CL/0.250, the number came out really large? is that right?

Yes, the number is a large one. A couple of words of caution.
1. AGCL and AgCl are two different things. The same goes for AGI versus AgI. You need to use more caps to begin a sentence and fewer caps for symbols.
2. I don't believe either of your values for Ksp and that will affect the ratio you calculated (although, I agree it is a large number).