11) AgCNGs) is dissolved in 0.200 M NH3(aq). Ksp for AgCN (s 1.2 x 10-16 & Krfor
ID: 534758 • Letter: 1
Question
11) AgCNGs) is dissolved in 0.200 M NH3(aq). Ksp for AgCN (s 1.2 x 10-16 & Krfor Ag(NH)2 (aq) 1.6 x 10 A) W the solubility product expression for AgCNGs (i e, write the reaction for AgCN(s) rite dissolving in aqueous solution). You must include state B) Write the formation expression, for the complex ion. C) Determine the solubility of AgCN(s) when dissolved 0.200 M NH,(aq). Answer: 8.76 x 10 in 1.2 x Step 1 add up the two ex pression no change k Ag CN table brc 2, NH nly one is Ag (NH 2, NH C. N involve cl Step 2: 1 Co. 2 -2.x)Explanation / Answer
11)
AgCN (s) ----------------> Ag+ + CN- Ksp = 1.2 x 10^-16
Ag+ + 2 NH3 ---------------> Ag(NH3)2+ (aq) Kf = 1.6 x 10^7
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AgCN (s) + 2 NH3 ------------> Ag(NH3)2+ (aq) + CN- (aq) , Keq = Ksp x Kf
Keq = 1.2 x 10^-16 x 1.6 x 10^7
= 1.92 x 10^-9
AgCN (s) + 2 NH3 ------------> Ag(NH3)2+ (aq) + CN- (aq)
2 1 1
0.2 - 2x x x
Keq = x^2 / (0.2 - 2x )^2
1.92 x 10^-9 = x^2 / (0.2 - 2x )^2
x / 0.2 - 2x = 4.38 x 10^-5
x = 8.76 x 10^-6 - 8.76 x 10^-5 x
x = 8.76 x 10^-6
solubility of AgCN = 8.76 x 10^-6 M