난용성염의 용해도 평형. Cu4(OH)6(SO4)

난용성염의 용해도 평형. Cu4(OH)6(SO4)

 

 

Find [Cu^2+] in a solution saturated with Cu4(OH)6(SO4)

if [OH^-] is fixed at 1.0×10^-6 M.

 

Cu4(OH)6(SO4)(s) ⇌ 4Cu^2+(aq) + 6OH^-(aq) + SO4^2-(aq) ... Ksp = 2.3×10^-69

 

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ICE table

 

.... Cu4(OH)6(SO4) ⇌ . 4Cu^2+ . + . 6OH^- . + . SO4^2-

초기(I) .......................... 0 .............. 0 .............. 0

변화(C) ....................... +4x ........... +6x ........... +x

평형(E) ........................ 4x ....... 1.0×10^-6 ....... x

 

( ∵ [OH^-] is fixed at 1.0×10^-6 M )

 

 

Ksp = [Cu^2+]^4 • [OH^-]^6 • [SO4^2-] = 2.3×10^-69

= (4x)^4 • (1.0×10^-6)^6 • x = (2.56×10^-34) x^5

 

x = [(2.3×10^-69) / (2.56×10^-34)]^(1/5)

= 9.79×10^-8 M

 

[Cu^2+] = 4x = 4(9.79×10^-8)

= 3.92×10^-7 M

 

 

답: 3.9×10^-7 M