Final answer:
The equilibrium constant for the solubility of FeCO₃ in NaCN can be determined by considering the formation of the complex ion Fe(CN)₆⁴⁻ using the given Kf value. The equilibrium expression can be set up and the concentration of Fe²⁺ can be expressed in terms of [Fe(CN)₆⁴⁻] using the Kf value. Substituting the values will give the equilibrium constant.
Step-by-step explanation:
The equilibrium constant for the solubility of FeCO₃ in NaCN can be determined by considering the formation of the complex ion Fe(CN)₆⁴⁻. The equation for the formation of Fe(CN)₆⁴⁻ is:
Fe²⁺(aq) + 6CN⁻(aq) → Fe(CN)₆⁴⁻
Using the given Kf value of Fe(CN)₆⁴⁻ (1.5 × 10³⁵), we can set up the equilibrium expression:
Ksp = [Fe(CN)₆⁴⁻] = [Fe²⁺][CN⁻]⁶
Since we are looking for the equilibrium constant for the solubility of FeCO₃, we can express the concentration of Fe²⁺ in terms of [Fe(CN)₆⁴⁻] using the equation:
[Fe²⁺] = Kf / [CN⁻]⁶
Substituting the given Kf value (1.5 × 10³⁵) and the concentration of cyanide ion ([CN⁻]) into the equation will give us the equilibrium constant for the solubility of FeCO₃ in NaCN.