Appendix K Formation Constants for Complex Ions

Formation Constants for Complex Ions

Equilibrium	K_f
${Al}^{3+} + 6 F^{−} ⇌ {[{AlF}_{6}]}^{3−}$	7 $\times$ 10¹⁹
${Cd}^{2+} + 4 {NH}_{3} ⇌ {[Cd {({NH}_{3})}_{4}]}^{2 +}$	1.3 $\times$ 10⁷
${Cd}^{2+} + 4 {CN}^{−} ⇌ {[Cd {(CN)}_{4}]}^{2−}$	3 $\times$ 10¹⁸
${Co}^{2+} + 6 {NH}_{3} ⇌ {[Co {({NH}_{3})}_{6}]}^{2+}$	1.3 $\times$ 10⁵
${Co}^{3+} + 6 {NH}_{3} ⇌ {[Co {({NH}_{3})}_{6}]}^{3+}$	2.3 $\times$ 10³³
${Cu}^{+} + 2 {CN}^{-} ⇌ {[Cu {(CN)}_{2}]}^{-}$	1.0 $\times$ 10¹⁶
${Cu}^{2+} + 4 {NH}_{3} ⇌ {[Cu {({NH}_{3})}_{4}]}^{2+}$	1.7 $\times$ 10¹³
${Fe}^{2+} + 6 {CN}^{−} ⇌ {[Fe {(CN)}_{6}]}^{4−}$	1.5 $\times$ 10³⁵
${Fe}^{3+} + 6 {CN}^{−} ⇌ {[Fe {(CN)}_{6}]}^{3−}$	2 $\times$ 10⁴³
${Fe}^{3+} + 6 {SCN}^{−} ⇌ {[Fe {(SCN)}_{6}]}^{3−}$	3.2 $\times$ 10³
${Hg}^{2+} + 4 {Cl}^{−} ⇌ {[{HgCl}_{4}]}^{2−}$	1.1 $\times$ 10¹⁶
${Ni}^{2+} + 6 {NH}_{3} ⇌ {[Ni {({NH}_{3})}_{6}]}^{2+}$	2.0 $\times$ 10⁸
${Ag}^{+} + 2 {Cl}^{−} ⇌ {[{AgCl}_{2}]}^{-}$	1.8 $\times$ 10⁵
${Ag}^{+} + 2 {CN}^{−} ⇌ {[Ag {(CN)}_{2}]}^{-}$	1 $\times$ 10²¹
${Ag}^{+} + 2 {NH}_{3} ⇌ {[Ag {({NH}_{3})}_{2}]}^{+}$	1.7 $\times$ 10⁷
${Zn}^{2+} + 4 {CN}^{−} ⇌ {[Zn {(CN)}_{4}]}^{2−}$	2.1 $\times$ 10¹⁹
${Zn}^{2+} + 4 {OH}^{−} ⇌ {[Zn {(OH)}_{4}]}^{2−}$	2 $\times$ 10¹⁵
${Fe}^{3+} + {SCN}^{−} ⇌ {[Fe (SCN)]}^{2+}$	8.9 $\times$ 10²
${Ag}^{+} + 4 {SCN}^{−} ⇌ {[Ag {(SCN)}_{4}]}^{3−}$	1.2 $\times$ 10¹⁰
${Pb}^{2+} + 4 I^{−} ⇌ {[{PbI}_{4}]}^{2−}$	3.0 $\times$ 10⁴
${Pt}^{2+} + 4 {Cl}^{−} ⇌ {[{PtCl}_{4}]}^{2−}$	1 $\times$ 10¹⁶
${Cu}^{2+} + 4 {CN}^{-} ⇌ {[Cu {(CN)}_{4}]}^{2−}$	1.0 $\times$ 10²⁵
${Co}^{2+} + 4 {SCN}^{−} ⇌ {[Co {(SCN)}_{4}]}^{2−}$	1 $\times$ 10³

Table K1