[Ag(NH3)2]++2H+=Ag++2NH4+
K=[Ag+]×[NH4+]^2÷{[Ag(NH3)2+]×[H+]^2}
=[Ag+]×[NH4+]^2×[OH]^2/{[Ag(NH3)2+]×[H+]^2×[OH-]^2}
=[Ag+]×[NH4+]^2×[OH]^2/{[Ag(NH3)2+]×Kw^2}
=[NH4+]^2×[OH]^2/{[Ag(NH3)2+]÷[Ag+]×Kw^2}
=[NH4+]^2×[OH]^2÷[NH3]^2/{[Ag(NH3)2+]÷[Ag+]÷[NH3]^2×Kw^2}
=KbNH3^2/{K稳×Kw^2}
=(1.77*10^-5))^2/{10^7.40*10^-28}
=1.25*10^11
K很大,说明基本完全反应
[Ag(NH3)2]++2H+=Ag++2NH4+
0.2V0.6V00
00.2V0.2V0.4V
因此溶液中[H+]=0.2V/2V=0.1mol/L
[Ag+]=0.2V/2V=0.1mol/L
[NH4+]=0.4V/2V=0.2mol/L
K很大,说明基本完全反应,溶液中[Ag(NH3)2]+浓度很小,可以认为[H+]、[Ag+]、[NH4+]基本不变
设[Ag(NH3)2]+为x
[Ag(NH3)2]++2H+=Ag++2NH4+
x0.10.10.2
K=[Ag+]×[NH4+]^2÷{[Ag(NH3)2+]×[H+]^2}
=0.1×(0.2)^2÷{x×(0.1)^2}=1.25*10^11
x=3.2*10^-12mol/L
即[Ag(NH3)2]+的浓度=3.2*10^-12mol/L