Potassium chromate is slowly added to a solution containing 0.20 M AgNO₃ and 0.20 M Ba(NO₃)₂.Describe what happens if the K_sp for Ag₂CrO₄ is 1.1 × 10^-12 and the K_sp of BaCrO₄ is 1.2 × 10^-10. A)The BaCrO₄ precipitates first out of solution. B)The Ag₂CrO₄ precipitates first out of solution and then BaCrO₄ precipitates. C)Both BaCrO₄ and Ag₂CrO₄ precipitate simultaneously out of solution. D)Neither BaCrO₄ nor Ag₂CrO₄ precipitates out of solution.

Question

Quizplus · Accepted Answer

When potassium chromate is added to the solution containing AgNO3 and Ba(NO3)2, the following reactions take place:
AgNO3 + K2CrO4 → Ag2CrO4↓ + 2KNO3
Ba(NO3)2 + K2CrO4 → BaCrO4↓ + 2KNO3
The solubility product constant (Ksp) of Ag2CrO4 is much smaller than that of BaCrO4. So, Ag2CrO4 precipitates first out of the solution until all of the Ag+ ions are consumed. After that, BaCrO4 precipitates out of the solution until all of the Ba2+ and CrO42- ions are consumed. Therefore, the correct answer is B.

Potassium Chromate Is Slowly Added to a Solution Containing 0