010 M Potassium Chromate Is Slowly Added to a Solution

Multiple Choice

0.10 M potassium chromate is slowly added to a solution containing 0.50 M AgNO₃ and 0.50 M Ba(NO₃) ₂.What is the Ag⁺ concentration when BaCrO₄ just starts to precipitate? The K_sp for Ag₂CrO₄ and BaCrO₄ are 1.1 × 10^-12 and 1.2 × 10^-10,respectively.

A) 6.5 × 10^-5 M
B) 1.3 × 10^-4 M
C) 3.2 × 10^-4 M
D) 6.8 × 10^-2 M