The Charge Balance Equation for the Solubility of Cobalt Sulfide

Multiple Choice

The charge balance equation for the solubility of cobalt sulfide is [H⁺] + 2 [Co²⁺] = 2 [S²⁻] + [OH⁻]
To determine a more accurate solubility for cobalt sulfide,additional equilibria must be written for cobalt(II) and sulfide in solution.Which of the charge balance equations below is the only valid charge balance equation?

A) [H⁺] + 2 [Co²⁺] + [CoOH⁺] + 3 [CoH³⁺] = 2 [S²⁻] + [HS⁻] + [OH⁻]
B) [H⁺] + 2 [Co²⁺] + [CoOH⁺] = 2 [S²⁻] + [HS⁻] + [OH⁻] + 3 [SOH³⁻]
C) [H⁺] + 2 [Co²⁺] + [CoOH⁺] = 2 [S²⁻] + [HS⁻] + [OH⁻]
D) [H⁺] + 2 [Co²⁺] + 3 [CoH³⁺] = 2 [S²⁻] + [HS⁻] + [OH⁻] + 3 [SOH³⁻]
E) [H⁺] + 2 [Co²⁺] + [CoOH⁺] + 3 [CoH³⁺] = 2 [S²⁻] + [HS⁻] + [OH⁻] + 3 [SOH³⁻]