Question

Write charge balance equations for (a) a standard solution if Bi2S3; and (b) a solution of Na2S.

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Answer 1

Number of +ve = Number of -ve

(a) Bi₂S₃ <--> 2Bi³⁺ + 3S^2-

       H₂O <--> H⁺ + OH^-

Charge balance equation is: [H⁺] + 2[Bi³⁺] = 3[S^2-] + [OH^-]

(b) Na₂S <--> 2Na⁺ + S^2-

       H₂O <--> H⁺ + OH^-

Charge balance equation is: [H⁺] + 2[Na⁺] = [S^2-] + [OH^-]