Answer to Question #151915 in Organic Chemistry for Raizsel Jayn

Question

If K2CrO4 is added to a solution containing 10grams of each of Ag+ and Pb2+ per liter, which ion will precipitate first?

Equations: Ag2CrO4 Ag+ +CrO4

-

Ksp Ag2CrO4 = 9.8x10-12

MWAg= 108 g/mol MWCr= 52g/mol MWo=16g/mol

PbCrO4 Pb2+ +CrO4

-2

Ksp PbCrO4= 2x10-14

MWPb= 204 g/mol

Answer 1

The salt with low KSP value precipitates first. KSP of PbCrO4= 2×10-14 is least. So Pb+2 is precipitates first