A solution of AgNO3 (1 x 10-6 molar) is prepared. To this is added K2CrO4 until precipitation of Ag2CrO4 begins. The Ksp of Ag2 CrO4 is 9 X 10-12.

Addition of NaCl will bring about:

1 answer

NaCl will cause AgCl to ppt.
AgCl is more insoluble than Ag2CrO4. If enough AgCl is added the Ag2CrO4 will dissolve and the color will change from red to white.