2.盐效应 I增大，y减小，【S]=a，溶解度增大 2 Kp0=aMaA K=[M][A]=4M= YM·YA YM'YA 3.酸效应 沉淀为弱酸盐时，aAm大，溶解度增加 CaC204=Ca2++C2042 H S S=C20,21 S2=[Ca2+][C201=Ksp=Ksp a C202 2. 盐效应 3. 酸效应 M A 0 sp K = a ⋅ a CaC2O4 = Ca2+ + C2O42- S S =[C2O42-' ] H+ S2 = [Ca2+] [C2O42-' ] = Ksp '= Ksp · α C2O4 2- (H) 0 sp M A 0 sp M A M A sp [M][A] K a a K K > ⋅ = ⋅ ⋅ = = γ γ γ γ γ a I 增大， 减小 ， γ [ S ] = ，溶解度增大 沉淀为弱酸盐时,αA(H) 大 , 溶解度增加