A solution contains both 0.015 M Mn²⁺ and 0.015 M Ni²⁺. If K₂CO₃ is added dropwise to the solution, what is the molarity of CO₃^2– when the second cation starts to precipitate? (K_sp MnCO₃ = 2.24×10^–11, K_sp NiCO₃ = 1.42×10^–7)

A 0.25 M HNO₃ solution contains 0.020 M Zn²⁺ and 0.020 M Ni²⁺. Can bubbling H₂S through the solution separate Zn²⁺ from Ni²⁺? The [H₂S] in a saturated solution of H₂S is approximately 0.10 M. (K_spa ZnS = 1.7 × 10⁻², K_spa NiS = 3.2)

If 75 mL of a solution made by dissolving 10.0 g of Ba(OH)₂(K_sp = 5.0×10^–3) in 300 mL of water was added to each of the beakers below, which beaker will a precipitate form? What is the identity of the precipitates that formed?

What is the precipitate formed when 0.012 M Na₂SO₄ is mixed with 0.018 M Ba(NO₃)₂?