Given the solubility product constant (Ksp) of NiS is 3.0 x 10^-15, determine the molar solubility of NiS in 0.052 M K2C2O4.

• A. 1.2 x 10^-7 M
• B. 5.8 x 10^-8 M
• C. 2.3 x 10^-6 M
• D. 4.5 x 10^-5 M

Answer: (B)

Verified step by step guidance

1. Start by writing the balanced dissolution equation for NiS: NiS(s) ⇌ Ni²⁺(aq) + S²⁻(aq).
2. Express the solubility product constant (Ksp) for NiS in terms of the concentrations of the ions: Ksp = [Ni²⁺][S²⁻].
3. Let the molar solubility of NiS be 's'. Then, [Ni²⁺] = s and [S²⁻] = s. Substitute these into the Ksp expression: Ksp = s².
4. Since NiS is dissolving in a solution containing K2C2O4, consider any common ion effect. However, K2C2O4 does not provide Ni²⁺ or S²⁻ ions, so the common ion effect does not apply here.
5. Solve for 's' using the Ksp value: s = √(Ksp). Substitute Ksp = 3.0 x 10⁻¹⁵ into the equation to find the molar solubility of NiS.