[{"data":1,"prerenderedAt":195},["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":33,"entryCount":164,"source":165,"notes":168,"relatedTopics":173,"relatedElements":178,"seoKeywords":179,"relatedReferences":187,"tableTitle":190,"tableDescription":191,"seoTitle":7,"filters":192},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.","Formation constants (Kf) for common complex ions at 25 °C, with equilibria, for ligand-exchange and complex-ion solubility problems.",[13,17,20,23,25,29],{"key":14,"label":15,"type":16},"complex","Complex Ion","chem",{"key":18,"label":19,"type":16},"metal","Metal",{"key":21,"label":22,"type":16},"ligand","Ligand",{"key":9,"label":24,"type":16},"Formation Equilibrium",{"key":26,"label":27,"type":16,"sortType":28},"Kf","Kf (25 °C)","numeric",{"key":30,"label":31,"type":32,"sortType":28},"logKf","log Kf","text",[34,41,48,54,60,65,71,76,82,87,93,99,105,111,116,121,127,133,138,143,150,154,159],{"complex":35,"metal":36,"ligand":37,"equilibrium":38,"Kf":39,"logKf":40},"[AlF₆]³⁻","Al","F⁻","Al³⁺ + 6 F⁻ ⇌ [AlF₆]³⁻","7 × 10¹⁹","19.8",{"complex":42,"metal":43,"ligand":44,"equilibrium":45,"Kf":46,"logKf":47},"[Cd(NH₃)₄]²⁺","Cd","NH₃","Cd²⁺ + 4 NH₃ ⇌ [Cd(NH₃)₄]²⁺","1.3 × 10⁷","7.1",{"complex":49,"metal":43,"ligand":50,"equilibrium":51,"Kf":52,"logKf":53},"[Cd(CN)₄]²⁻","CN⁻","Cd²⁺ + 4 CN⁻ ⇌ [Cd(CN)₄]²⁻","3 × 10¹⁸","18.5",{"complex":55,"metal":56,"ligand":44,"equilibrium":57,"Kf":58,"logKf":59},"[Co(NH₃)₆]²⁺","Co","Co²⁺ + 6 NH₃ ⇌ [Co(NH₃)₆]²⁺","1.3 × 10⁵","5.1",{"complex":61,"metal":56,"ligand":44,"equilibrium":62,"Kf":63,"logKf":64},"[Co(NH₃)₆]³⁺","Co³⁺ + 6 NH₃ ⇌ [Co(NH₃)₆]³⁺","2.3 × 10³³","33.4",{"complex":66,"metal":67,"ligand":50,"equilibrium":68,"Kf":69,"logKf":70},"[Cu(CN)₂]⁻","Cu","Cu⁺ + 2 CN⁻ ⇌ [Cu(CN)₂]⁻","1 × 10¹⁶","16.0",{"complex":72,"metal":67,"ligand":44,"equilibrium":73,"Kf":74,"logKf":75},"[Cu(NH₃)₄]²⁺","Cu²⁺ + 4 NH₃ ⇌ [Cu(NH₃)₄]²⁺","1.7 × 10¹³","13.2",{"complex":77,"metal":78,"ligand":50,"equilibrium":79,"Kf":80,"logKf":81},"[Fe(CN)₆]⁴⁻","Fe","Fe²⁺ + 6 CN⁻ ⇌ [Fe(CN)₆]⁴⁻","1.5 × 10³⁵","35.2",{"complex":83,"metal":78,"ligand":50,"equilibrium":84,"Kf":85,"logKf":86},"[Fe(CN)₆]³⁻","Fe³⁺ + 6 CN⁻ ⇌ [Fe(CN)₆]³⁻","2 × 10⁴³","43.3",{"complex":88,"metal":78,"ligand":89,"equilibrium":90,"Kf":91,"logKf":92},"[Fe(SCN)₆]³⁻","SCN⁻","Fe³⁺ + 6 SCN⁻ ⇌ [Fe(SCN)₆]³⁻","3.2 × 10³","3.5",{"complex":94,"metal":95,"ligand":96,"equilibrium":97,"Kf":98,"logKf":70},"[HgCl₄]²⁻","Hg","Cl⁻","Hg²⁺ + 4 Cl⁻ ⇌ [HgCl₄]²⁻","1.1 × 10¹⁶",{"complex":100,"metal":101,"ligand":44,"equilibrium":102,"Kf":103,"logKf":104},"[Ni(NH₃)₆]²⁺","Ni","Ni²⁺ + 6 NH₃ ⇌ [Ni(NH₃)₆]²⁺","2 × 10⁸","8.3",{"complex":106,"metal":107,"ligand":96,"equilibrium":108,"Kf":109,"logKf":110},"[AgCl₂]⁻","Ag","Ag⁺ + 2 Cl⁻ ⇌ [AgCl₂]⁻","1.8 × 10⁵","5.3",{"complex":112,"metal":107,"ligand":50,"equilibrium":113,"Kf":114,"logKf":115},"[Ag(CN)₂]⁻","Ag⁺ + 2 CN⁻ ⇌ [Ag(CN)₂]⁻","1 × 10²¹","21.0",{"complex":117,"metal":107,"ligand":44,"equilibrium":118,"Kf":119,"logKf":120},"[Ag(NH₃)₂]⁺","Ag⁺ + 2 NH₃ ⇌ [Ag(NH₃)₂]⁺","1.7 × 10⁷","7.2",{"complex":122,"metal":123,"ligand":50,"equilibrium":124,"Kf":125,"logKf":126},"[Zn(CN)₄]²⁻","Zn","Zn²⁺ + 4 CN⁻ ⇌ [Zn(CN)₄]²⁻","2.1 × 10¹⁹","19.3",{"complex":128,"metal":123,"ligand":129,"equilibrium":130,"Kf":131,"logKf":132},"[Zn(OH)₄]²⁻","OH⁻","Zn²⁺ + 4 OH⁻ ⇌ [Zn(OH)₄]²⁻","2 × 10¹⁵","15.3",{"complex":134,"metal":78,"ligand":89,"equilibrium":135,"Kf":136,"logKf":137},"[Fe(SCN)]²⁺","Fe³⁺ + SCN⁻ ⇌ [Fe(SCN)]²⁺","8.9 × 10²","2.9",{"complex":139,"metal":107,"ligand":89,"equilibrium":140,"Kf":141,"logKf":142},"[Ag(SCN)₄]³⁻","Ag⁺ + 4 SCN⁻ ⇌ [Ag(SCN)₄]³⁻","1.2 × 10¹⁰","10.1",{"complex":144,"metal":145,"ligand":146,"equilibrium":147,"Kf":148,"logKf":149},"[PbI₄]²⁻","Pb","I⁻","Pb²⁺ + 4 I⁻ ⇌ [PbI₄]²⁻","3 × 10⁴","4.5",{"complex":151,"metal":152,"ligand":96,"equilibrium":153,"Kf":69,"logKf":70},"[PtCl₄]²⁻","Pt","Pt²⁺ + 4 Cl⁻ ⇌ [PtCl₄]²⁻",{"complex":155,"metal":67,"ligand":50,"equilibrium":156,"Kf":157,"logKf":158},"[Cu(CN)₄]²⁻","Cu²⁺ + 4 CN⁻ ⇌ [Cu(CN)₄]²⁻","1 × 10²⁵","25.0",{"complex":160,"metal":56,"ligand":89,"equilibrium":161,"Kf":162,"logKf":163},"[Co(SCN)₄]²⁻","Co²⁺ + 4 SCN⁻ ⇌ [Co(SCN)₄]²⁻","1 × 10³","3.0",23,{"label":166,"url":167},"OpenStax Chemistry 2e, Appendix K — Formation Constants for Complex Ions","https://openstax.org/books/chemistry-2e/pages/k-formation-constants-for-complex-ions",[169,170,171,172],"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, so 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.","This table is a general reference.",[174,175,176,177],"solubility-and-complex-ion-equilibria","entropy-and-free-energy","electrochemistry","coordination-chemistry",[107,67,123,78,56,101,43,95,36],[180,181,182,183,184,185,186],"formation constant table","Kf values complex ions","stability constant","complex ion equilibrium","silver ammine complex","log Kf table","dissociation constant complex",[188,189],"solubility-product-constants","spectrochemical-series","Complex-Ion Formation Constants at 25 °C","A large Kf means the complex forms nearly completely; use it for ligand-exchange and solubility problems.",[193,194],{"key":18,"label":19},{"key":21,"label":22},1787246032711]