0.10 M potassium chromate is slowly added to a solution containing 0.10 M AgNO₃ and 0.10 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)3.0 × 10^-2 M

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Quizplus · Accepted Answer

When BaCrO₄ starts to precipitate, [CrO₄²⁻] = √(Ksp of BaCrO₄ / [Ba²⁺]) = √(1.2 × 10⁻¹⁰ / 0.10) = 1.1 × 10⁻⁴ M. For Ag₂CrO₄, [Ag⁺] = √(Ksp of Ag₂CrO₄ / [CrO₄²⁻]) = √(1.1 × 10⁻¹² / 1.1 × 10⁻⁴) = 3.0 × 10⁻² M.

010 M Potassium Chromate Is Slowly Added to a Solution