Question

Calculate Kc of the following reaction: CuBr(s)+Br-(aq)----> CuBr2-(aq) The solubility product constant, Ksp, for CuBr is 6.27× 10–9 and the overall formation constant, Kf (β2), for CuBr2– is 8.0× 105.

Answer 1

CuBr(s)+Br-(aq)----> CuBr2^-(aq)

Kc   = [CuBr^2-]/[Br^-]                    [solid CuBr, [CuBr] = 1]

CuBr(s) ---------------> Cu^+ (aq) + Br^-

Ksp   = [Cu^+][Br^-]

Cu^+ (aq) + 2Br^-(aq) ----------------------> CuBr2^-(aq)

    Kf = [CuBr2^-]/[Cu^+][Br^-]^2

KsP*Kf   = [Cu^+][Br^-]*[CuBr2^-]/[Cu^+][Br^-]^2

               = [CuBr^2-]/[Br^-]   

Ksp*Kf    = Kc

Kc    = Ksp*Kf   

         = 6.27*10^-9 * 8*10^5   = 0.005016 >>>>>>answer