CuS(s) ⇄ Cu₂⁺ (aq) + S₂⁻ (aq) Ksp = 6.0 x 10⁻³⁷
Cu₂⁺(aq) + 4CN⁻ (aq) ⇄ Cu(CN)₄²⁻ (aq) Kf = 1.0 x 10²⁵
When CN⁻ is added to CuS(s), a combination of these reactions occurs
CuS(s) + 4CN⁻ (aq) ⇄ Cu(CN)₄²⁻ (aq) + S₂⁻ (aq)
What mass of CuS (95.6 g/mol) can dissolve in 66.5 L of 5.1 M KCN solution?
