Can somebody check this for me??
Ksp
AgCl 1.8x10^-10
Ag2CrO4 1.0x10^-12
AgI 1.0x10^-16
Ag3Po4 1.0x10^-16
1. calc the [Ag+] and [Cl-] at equivalence point.
I got 1.3x10^-5
2. Calc. the [CrO4-2] required to precipitate AgCr04 if the [Ag+] equals the conc. cal. in #1
I got 5.56x10^-3
3. calc the [Ag+] in sat. solutions of AgI and Ag3PO4.
I got 1.32x10^-4 for Ag3PO4 and 1x10^-8 for AgI
4. can sodiun chromate be used as an indicator for titration of I- and Ag+? Why?
No, Ksp for Ag2CrO4 larger than Ksp for AgI, AgI would ppt.
5. can sodium chromate be used as an indicator for titration of PO4-3 with Ag+. Why?
No, Ksp for Ag2CrO4 is larger than Ksp for Ag3PO4 so, Ag3PO4 would ppt.
1,2,&3 are good answers.
4&5. Actually, you may not compare solubility products as a point of departure for solubility UNLESS the salts are thw same type. That is, you may compare AgCl and BaSO4 or Ag2CrO4 and Ag2CO3, but you may not compare Ag2CrO4 and AgCl. And I'm not sure about the answer either. The whole point in the AgCl titration using Ag2CrO4 as indicator is that ALL the AgCl ppts, THEN THE NEXT DROP of Ag^+ titrant turns the CrO4^= to Ag2CrO4. So you WANT the AgI and Ag3PO4 to ppt before the next drop turns the Ag2CrO4.