Appendix L: Formation Constants for Complex Ions
Formation Constants – Complex Ions
| Equilibrium | Kf |
|---|---|
| [latex]\text{Al}^{3+}\;+\;6\text{F}^{-}\;{\rightleftharpoons}\;[\text{AlF}_6]^{3-}[/latex] | 7 × 1019 |
| [latex]\text{Cd}^{2+}\;+\;4\text{NH}_3\;{\rightleftharpoons}\;[\text{Cd(NH}_3\text{)}_4]^{2+}[/latex] | 1.3 × 107 |
| [latex]\text{Cd}^{2+}\;+\;4\text{CN}^{-}\;{\rightleftharpoons}\;[\text{Cd(CN)}_4]^{2-}[/latex] | 3 × 1018 |
| [latex]\text{Co}^{2+}\;+\;6\text{NH}_3\;{\rightleftharpoons}\;[\text{Co(NH}_3\text{)}_6]^{2+}[/latex] | 1.3 × 105 |
| [latex]\text{Co}^{3+}\;+\;6\text{NH}_3\;{\rightleftharpoons}\;[\text{Co(NH}_3\text{)}_6]^{3+}[/latex] | 2.3 × 1033 |
| [latex]\text{Cu}^+\;+\;2\text{CN}\;{\rightleftharpoons}\;[\text{Cu(CN)}_2]^{-}[/latex] | 1.0 × 1016 |
| [latex]\text{Cu}^{2+}\;+\;4\text{NH}_3\;{\rightleftharpoons}\;[\text{Cu(NH}_3\text{)}_4]^{2+}[/latex] | 1.7 × 1013 |
| [latex]\text{Fe}^{2+}\;+\;6\text{CN}^{-}\;{\rightleftharpoons}\;[\text{Fe(CN)}_6]^{4-}[/latex] | 1.5 × 1035 |
| [latex]\text{Fe}^{3+}\;+\;6\text{CN}^{-}\;{\rightleftharpoons}\;[\text{Fe(CN)}_6]^{3-}[/latex] | 2 × 1043 |
| [latex]\text{Fe}^{3+}\;+\;6\text{SCN}^{-}\;{\rightleftharpoons}\;[\text{Fe(SCN)}_6]^{3-}[/latex] | 3.2 × 103 |
| [latex]\text{Hg}^{2+}\;+\;4\text{Cl}^{-}\;{\rightleftharpoons}\;[\text{HgCl}_4]^{2-}[/latex] | 1.1 × 1016 |
| [latex]\text{Ni}^{2+}\;+\;6\text{NH}_3\;{\rightleftharpoons}\;[\text{Ni(NH}_3\text{)}_6]^{2+}[/latex] | 2.0 × 108 |
| [latex]\text{Ag}^{+}\;+\;2\text{Cl}^{-}\;{\rightleftharpoons}\;[\text{AgCl}_2]^{-}[/latex] | 1.8 × 105 |
| [latex]\text{Ag}^{+}\;+\;2\text{CN}^{-}\;{\rightleftharpoons}\;[\text{Ag(CN)}_2]^{-}[/latex] | 1 × 1021 |
| [latex]\text{Ag}^{+}\;+\;2\text{NH}_3\;{\rightleftharpoons}\;[\text{Ag(NH}_3\text{)}_2]^{+}[/latex] | 1.7 × 107 |
| [latex]\text{Zn}^{2+}\;+\;4\text{CN}^{-}\;{\rightleftharpoons}\;[\text{Zn(CN)}_4]^{2-}[/latex] | 2.1 × 1019 |
| [latex]\text{Zn}^{2+}\;+\;4\text{OH}^{-}\;{\rightleftharpoons}\;[\text{Zn(OH)}_4]^{2-}[/latex] | 2 × 1015 |
| [latex]\text{Fe}^{3+}\;+\;\text{SCN}^{-}\;{\rightleftharpoons}\;[\text{Fe(SCN)}]^{2+}[/latex] | 8.9 × 102 |
| [latex]\text{Ag}^+\;+\;4\text{SCN}^{-}\;{\rightleftharpoons}\;[\text{Ag(SCN)}_4]^{3-}[/latex] | 1.2 × 1010 |
| [latex]\text{Pb}^{2+}\;+\;4\text{I}^{-}\;{\rightleftharpoons}\;[\text{PbI}_4]^{2-}[/latex] | 3.0 × 104 |
| [latex]\text{Pt}^{2+}\;+\;4\text{Cl}^{-}\;{\rightleftharpoons}\;[\text{PtCl}_4]^{2-}[/latex] | 1 × 1016 |
| [latex]\text{Cu}^{2+}\;+\;4\text{CN}\;{\rightleftharpoons}\;[\text{Cu(CN)}_4]^{2-}[/latex] | 1.0 × 1025 |
| [latex]\text{Co}^{2+}\;+\;4\text{SCN}^{-}\;{\rightleftharpoons}\;[\text{Co(SCN)}_4]^{2-}[/latex] | 1 × 103 |
Attribution & References
Except where otherwise noted, this page is adapted from “Appendix K: Formation Constants for Complex Ions ” In General Chemistry 1 & 2 by Rice University, a derivative of Chemistry (Open Stax) by Paul Flowers, Klaus Theopold, Richard Langley & William R. Robinson and is licensed under CC BY 4.0. Access for free at Chemistry (OpenStax)
