Molar solubility of AgCl in 0.50 M NH3

Molar solubility of AgCl in 0.50 M NH3

 

 

What is the molar solubility of AgCl in 0.50 M NH3?

Ksp for AgCl is 1.8×10^-10 and the Kf for Ag(NH3)2^+ is 1.7×10^7

 

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AgCl(s) ⇌ Ag^+(aq) + Cl^-(aq)

Ksp = [Ag^+][Cl^-] = 1.8×10^-10

 

Ag^+(aq) + 2NH3(aq) ⇌ Ag(NH3)2^+(aq)

Kf = [Ag(NH3)2^+] / [Ag^+][NH3]^2 = 1.7×10^7

 

 

AgCl(s) + 2NH3(aq) ⇌ Ag(NH3)2^+(aq) + Cl^-(aq)

Keq = [Ag(NH3)2^+][Cl^-] / [NH3]^2

= Ksp × Kf

= (1.8×10^-10) × (1.7×10^7)

= 0.00306

 

 

평형에서,

AgCl(s) + 2NH3(aq) ⇌ Ag(NH3)2^+(aq) + Cl^-(aq)

......... 0.50-2x ... x .............. x

 

 

Keq = [Ag(NH3)2^+][Cl^-] / [NH3]^2

= x^2 / (0.50-2x)^2 = 0.00306

 

(x / (0.50-2x))^2 = 0.00306

x / (0.50-2x) = (0.00306)^(1/2) = 0.0553173

x = 0.0276587 – 0.110635x

1.110635x = 0.0276587

x = 0.0276587 / 1.110635

= 0.0249035

= 0.025 M = [Cl^-] = [AgCl]

 

 

답: 0.025 M

 

 

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