例5在pH=10.0,[NH3]=0020mo/L时,用0.020mo/L EDTA标准溶液滴定0.020mo/Lcu2+溶液,计算滴定到达计 量点时的pCu”和pCu 解计量点时 CUsP=0.010mo/L NH3]=0010mo/L cu(NH)=1+β1NH3]+阝2NH2+阝3NH33 +4NH14 =1+10231+10398+10502+10532=10551 Igacu(NH3)=5. 51, pH=10.0B], IgaY(H)=0.45 IgK'cur= igKcur-Igacu(NH3)"Igay(H) =18.80-551-0.45=12849 例5 在pH=10.0, [NH3 ]=0.020mol/L时，用0.020mol/L EDTA标准溶液滴定0.020mol/L Cu2+溶液，计算滴定到达计 量点时的pCu’ 和pCu。 解 计量点时CCuSP=0.010mol/L [NH3 ]=0.010mol/L αCu(NH3)=1+β1 [NH3 ]+β2 [NH3 ] 2+β3 [NH3 ] 3 +β4 [NH3 ] 4 =1+102.31 +103.98 +105.02 +105.32=105.51 lgαCu(NH3)=5.51, pH=10.0时，lgαY(H)=0.45 lgK’ CuY= lgKCuY- lgαCu(NH3)- lgαY(H) =18.80-5.51-0.45=12.84