[{"data":1,"prerenderedAt":173},["ShallowReactive",2],{"reference-formation-constants":3},{"table":4},{"id":5,"slug":6,"title":7,"shortTitle":8,"category":9,"description":10,"metaDescription":11,"columns":12,"rows":27,"entryCount":140,"source":141,"notes":145,"relatedTopics":150,"relatedElements":155,"seoKeywords":165},15,"formation-constants","Formation Constants (Kf) for Complex Ions","Kf Values","Equilibrium","Formation (stability) constants Kf at 25 °C for common complex ions, each with its formation equilibrium. Large Kf values explain why complexation dissolves sparingly soluble salts: couple the dissolution with the formation equilibrium (K = Ksp × Kf) to compute solubility in the presence of a complexing agent.","Kf table: formation constants for complex ions at 25 °C — silver ammine, tetraamminecopper(II), hexacyanoferrate, and more — with formation equilibria and log Kf for complex-ion equilibrium calculations.",[13,17,20,23],{"key":14,"label":15,"type":16},"complex","Complex Ion","chem",{"key":18,"label":19,"type":16},"equilibrium","Formation Equilibrium",{"key":21,"label":22,"type":16},"Kf","Kf (25 °C)",{"key":24,"label":25,"type":26},"logKf","log Kf","text",[28,33,38,43,48,53,58,63,68,73,78,82,87,92,97,102,107,112,117,122,127,130,135],{"complex":29,"equilibrium":30,"Kf":31,"logKf":32},"[AlF₆]³⁻","Al³⁺ + 6 F⁻ ⇌ [AlF₆]³⁻","7 × 10¹⁹","19.8",{"complex":34,"equilibrium":35,"Kf":36,"logKf":37},"[Cd(NH₃)₄]²⁺","Cd²⁺ + 4 NH₃ ⇌ [Cd(NH₃)₄]²⁺","1.3 × 10⁷","7.1",{"complex":39,"equilibrium":40,"Kf":41,"logKf":42},"[Cd(CN)₄]²⁻","Cd²⁺ + 4 CN⁻ ⇌ [Cd(CN)₄]²⁻","3 × 10¹⁸","18.5",{"complex":44,"equilibrium":45,"Kf":46,"logKf":47},"[Co(NH₃)₆]²⁺","Co²⁺ + 6 NH₃ ⇌ [Co(NH₃)₆]²⁺","1.3 × 10⁵","5.1",{"complex":49,"equilibrium":50,"Kf":51,"logKf":52},"[Co(NH₃)₆]³⁺","Co³⁺ + 6 NH₃ ⇌ [Co(NH₃)₆]³⁺","2.3 × 10³³","33.4",{"complex":54,"equilibrium":55,"Kf":56,"logKf":57},"[Cu(CN)₂]⁻","Cu⁺ + 2 CN⁻ ⇌ [Cu(CN)₂]⁻","1 × 10¹⁶","16.0",{"complex":59,"equilibrium":60,"Kf":61,"logKf":62},"[Cu(NH₃)₄]²⁺","Cu²⁺ + 4 NH₃ ⇌ [Cu(NH₃)₄]²⁺","1.7 × 10¹³","13.2",{"complex":64,"equilibrium":65,"Kf":66,"logKf":67},"[Fe(CN)₆]⁴⁻","Fe²⁺ + 6 CN⁻ ⇌ [Fe(CN)₆]⁴⁻","1.5 × 10³⁵","35.2",{"complex":69,"equilibrium":70,"Kf":71,"logKf":72},"[Fe(CN)₆]³⁻","Fe³⁺ + 6 CN⁻ ⇌ [Fe(CN)₆]³⁻","2 × 10⁴³","43.3",{"complex":74,"equilibrium":75,"Kf":76,"logKf":77},"[Fe(SCN)₆]³⁻","Fe³⁺ + 6 SCN⁻ ⇌ [Fe(SCN)₆]³⁻","3.2 × 10³","3.5",{"complex":79,"equilibrium":80,"Kf":81,"logKf":57},"[HgCl₄]²⁻","Hg²⁺ + 4 Cl⁻ ⇌ [HgCl₄]²⁻","1.1 × 10¹⁶",{"complex":83,"equilibrium":84,"Kf":85,"logKf":86},"[Ni(NH₃)₆]²⁺","Ni²⁺ + 6 NH₃ ⇌ [Ni(NH₃)₆]²⁺","2 × 10⁸","8.3",{"complex":88,"equilibrium":89,"Kf":90,"logKf":91},"[AgCl₂]⁻","Ag⁺ + 2 Cl⁻ ⇌ [AgCl₂]⁻","1.8 × 10⁵","5.3",{"complex":93,"equilibrium":94,"Kf":95,"logKf":96},"[Ag(CN)₂]⁻","Ag⁺ + 2 CN⁻ ⇌ [Ag(CN)₂]⁻","1 × 10²¹","21.0",{"complex":98,"equilibrium":99,"Kf":100,"logKf":101},"[Ag(NH₃)₂]⁺","Ag⁺ + 2 NH₃ ⇌ [Ag(NH₃)₂]⁺","1.7 × 10⁷","7.2",{"complex":103,"equilibrium":104,"Kf":105,"logKf":106},"[Zn(CN)₄]²⁻","Zn²⁺ + 4 CN⁻ ⇌ [Zn(CN)₄]²⁻","2.1 × 10¹⁹","19.3",{"complex":108,"equilibrium":109,"Kf":110,"logKf":111},"[Zn(OH)₄]²⁻","Zn²⁺ + 4 OH⁻ ⇌ [Zn(OH)₄]²⁻","2 × 10¹⁵","15.3",{"complex":113,"equilibrium":114,"Kf":115,"logKf":116},"[Fe(SCN)]²⁺","Fe³⁺ + SCN⁻ ⇌ [Fe(SCN)]²⁺","8.9 × 10²","2.9",{"complex":118,"equilibrium":119,"Kf":120,"logKf":121},"[Ag(SCN)₄]³⁻","Ag⁺ + 4 SCN⁻ ⇌ [Ag(SCN)₄]³⁻","1.2 × 10¹⁰","10.1",{"complex":123,"equilibrium":124,"Kf":125,"logKf":126},"[PbI₄]²⁻","Pb²⁺ + 4 I⁻ ⇌ [PbI₄]²⁻","3 × 10⁴","4.5",{"complex":128,"equilibrium":129,"Kf":56,"logKf":57},"[PtCl₄]²⁻","Pt²⁺ + 4 Cl⁻ ⇌ [PtCl₄]²⁻",{"complex":131,"equilibrium":132,"Kf":133,"logKf":134},"[Cu(CN)₄]²⁻","Cu²⁺ + 4 CN⁻ ⇌ [Cu(CN)₄]²⁻","1 × 10²⁵","25.0",{"complex":136,"equilibrium":137,"Kf":138,"logKf":139},"[Co(SCN)₄]²⁻","Co²⁺ + 4 SCN⁻ ⇌ [Co(SCN)₄]²⁻","1 × 10³","3.0",23,{"label":142,"url":143,"license":144},"OpenStax Chemistry 2e, Appendix K — Formation Constants for Complex Ions","https://openstax.org/books/chemistry-2e/pages/k-formation-constants-for-complex-ions","CC BY 4.0",[146,147,148,149],"Kf is the equilibrium constant for FORMING the complex from the free metal ion and ligands; its inverse (1/Kf) is the dissociation constant Kd.","Very large Kf values (10¹⁰ and beyond) mean essentially complete complexation when excess ligand is present — the free metal-ion concentration becomes vanishingly small.","To dissolve a precipitate with a complexing agent, couple the equilibria: AgCl(s) + 2 NH₃ ⇌ [Ag(NH₃)₂]⁺ + Cl⁻ has K = Ksp × Kf.","ChemWhiz problems that need a Kf supply the value in the problem statement; this table is the general reference.",[151,152,153,154],"solubility-and-complex-ion-equilibria","entropy-and-free-energy","electrochemistry","coordination-chemistry",[156,157,158,159,160,161,162,163,164],"Ag","Cu","Zn","Fe","Co","Ni","Cd","Hg","Al",[166,167,168,169,170,171,172],"formation constant table","Kf values complex ions","stability constant","complex ion equilibrium","silver ammine complex","log Kf table","dissociation constant complex",1785108608471]