A solution is prepared by mixing 50.0 mL of 0.50 M Cu(NO₃)₂ with 50.0 mL of 0.50 M Co(NO₃)₂. Sodium hydroxide is added to the mixture. Which hydroxide precipitates first and what concentration of hydroxide ions present in solution will accomplish the separation? K_sp = 2.2 × 10^-20 for Cu(OH)₂, K_sp = 1.3 × 10^-15for Co(OH)₂ A) Co(OH)₂; [OH^-] = 6.9 × 10^-6 M B) Co(OH)₂; [OH^-] = 2.6 × 10^-7 M C) Cu(OH)₂; [OH^-] = 1.8 × 10^-7 M D) Cu(OH)₂; [OH^-] = 1.1 × 10^-9 M E) Cu(OH)₂; [OH^-] = 1.0 × 10^-17 M

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Quizplus · Accepted Answer

The Ksp value for Cu(OH)2 is smaller than that for Co(OH)2, indicating that Cu(OH)2 is less soluble than Co(OH)2. Therefore, Cu(OH)2 will precipitate first. To calculate the concentration of hydroxide ions required to precipitate Cu(OH)2, we can use the Ksp expression:Ksp = [Cu2+][OH-]22.2 × 10^-20 = [Cu2+][OH-]2[OH-] = 1.1 × 10^-9 M

A Solution Is Prepared by Mixing 50