累积稳定常数B B,=K1- [ML] [M][L] [ML]=B1[M][L] 房，=K2= 灯.IML2] [ML2] M[L]L可[L] [M[L]2 [ML2]=B2[M][L]2 B=KK2Kn= [ML [M[L]” [MLn]=Bn [M][L]
累积稳定常数 = = K 1 1 [ML] [M][L] [ML] = 1 [M] [L] 1 2 2 2 [ML] [ML ] [M][L] [ML][L] = = • K K [ML2 ]= 2 [M] [L]2 ● ● ● = • • • = n n n n K K K 1 2 [ML ] [M][L] [MLn ]= n [M] [L]n = 2 2 [ML ] [M][L]
5.3外界条件对EDTA与金属离子配合 物稳定性的影响 M MY(主反应) OH- MOH MA HY NY MHY MOHY ● ● ● 副反应 M(OH)p MAa M' (MY)' K(MY)= [(MY] 条件（稳定）常数 [M][YT
5.3 外界条件对EDTA与金属离子配合 物稳定性的影响 M + Y = MY(主反应) OHMOH ● ● ● M(OH)p A MA ● ● ● MAq M H+ HY ● ● ● H6Y N NY Y H+ OHMHY MOHY （ ） MY [(MY) ] (MY) = [M ][Y ] K 条件(稳定)常数 副 反 应
1.滴定剂的副反应系数 QY(H) aY(H) =[Y']Y]+HY]+[HY++[HY] [Y] [Y] x(Y) Y+IYIHB+YI[HB++YIIHB Y =1+H]β，+HB2+●●●+Hp。 [Y]= [YI [Y']=[Y]aY(H) CYm≥1 @Y(H) 酸效应系数
1. 滴定剂的副反应系数 a Y(H) [Y ] = [Y] 2 6 [Y] [HY] [H Y] [H Y] [Y] + + + • • • + = 2 6 1 2 6 [Y] [Y][H ] [Y][H ] [Y][H ] [Y] + + + + + + • • • + = 2 6 1 2 6 1 [H ] [H ] [H ] + + + = + + + • • • + Y(H) [Y'] [Y] = Y(H) [Y'] [Y] = Y(H) 1 酸效应系数 Y(H) 1 x(Y) =
2.金属离子的副反应系数M M(NH3) 1+NH3l8+[NH3]2B2+INH3]3 B3+[NH31B4 M(OH) 1+[OH]B+[OH]2B2+-[OH]T B
2. 金属离子的副反应系数M M(NH3)= M(OH)= 1+[OH] 1 +[OH]2 2 + - [OH]n n 1+[NH3 ]1+[NH3 ] 2 2+[NH3 ] 3 3+[NH3 ] 4 4
g&M(NH3)lg[NH曲线(p158) 14 Ig&M(NH3) 12 10 8 6 Ag 4 2 0 -3 -2 -1 0 1g [NH 3]
lgαM(NH3) ～lg[NH3 ]曲线 (p158) 0 2 4 6 8 10 12 14 -3 -2 -1 0 lg[NH 3 ] Cu Ag Ni Zn Cd Co lgαM(NH3)