[{"data":1,"prerenderedAt":198},["ShallowReactive",2],{"reference-weak-acid-base-constants":3},{"table":4},{"id":5,"slug":6,"title":7,"shortTitle":8,"category":9,"description":10,"metaDescription":11,"columns":12,"rows":32,"entryCount":175,"source":176,"notes":178,"relatedTopics":183,"relatedElements":189,"seoKeywords":190},12,"weak-acid-base-constants","Ka and Kb Values for Weak Acids and Bases","Ka / Kb Constants","Equilibrium","Acid-ionization (Ka) and base-ionization (Kb) constants at 25 °C for the weak acids, weak bases, and conjugate pairs used throughout the acid-base, buffer, hydrolysis, and titration topics. Use Ka × Kb = Kw = 1.0 × 10⁻¹⁴ to convert between a conjugate pair.","Reference table of Ka, pKa, Kb, and pKb values at 25 °C for common weak acids and bases — acetic acid, ammonia, formic acid, carbonic acid, and more — with the conjugate-pair conversion rule.",[13,17,21,24,26,28,30],{"key":14,"label":15,"type":16},"formula","Formula","chem",{"key":18,"label":19,"type":20},"name","Name","text",{"key":22,"label":23,"type":20},"type","Type",{"key":25,"label":25,"type":16},"Ka",{"key":27,"label":27,"type":20},"pKa",{"key":29,"label":29,"type":16},"Kb",{"key":31,"label":31,"type":20},"pKb",[33,40,45,50,55,60,65,70,75,80,85,90,95,99,104,110,116,121,126,131,136,140,145,150,155,160,165,170],{"formula":34,"name":35,"type":36,"Ka":37,"pKa":38,"Kb":39,"pKb":39},"CH₃COOH","Acetic acid","Weak acid","1.8 × 10⁻⁵","4.76","—",{"formula":41,"name":42,"type":36,"Ka":43,"pKa":44,"Kb":39,"pKb":39},"C₆H₅COOH","Benzoic acid","6.5 × 10⁻⁵","4.19",{"formula":46,"name":47,"type":36,"Ka":48,"pKa":49,"Kb":39,"pKb":39},"HCO₃⁻","Bicarbonate ion","4.68 × 10⁻¹¹","10.33",{"formula":51,"name":52,"type":36,"Ka":53,"pKa":54,"Kb":39,"pKb":39},"H₂CO₃","Carbonic acid","4.27 × 10⁻⁷","6.37",{"formula":56,"name":57,"type":36,"Ka":58,"pKa":59,"Kb":39,"pKb":39},"HCNO","Cyanic acid","3.47 × 10⁻⁴","3.46",{"formula":61,"name":62,"type":36,"Ka":63,"pKa":64,"Kb":39,"pKb":39},"H₂PO₄⁻","Dihydrogen phosphate ion","6.17 × 10⁻⁸","7.21",{"formula":66,"name":67,"type":36,"Ka":68,"pKa":69,"Kb":39,"pKb":39},"FCH₂COOH","Fluoroacetic acid","2.57 × 10⁻³","2.59",{"formula":71,"name":72,"type":36,"Ka":73,"pKa":74,"Kb":39,"pKb":39},"HCOOH","Formic acid","1.77 × 10⁻⁴","3.75",{"formula":76,"name":77,"type":36,"Ka":78,"pKa":79,"Kb":39,"pKb":39},"HCN","Hydrocyanic acid","4.9 × 10⁻¹⁰","9.31",{"formula":81,"name":82,"type":36,"Ka":83,"pKa":84,"Kb":39,"pKb":39},"HF","Hydrofluoric acid","7.2 × 10⁻⁴","3.14",{"formula":86,"name":87,"type":36,"Ka":88,"pKa":89,"Kb":39,"pKb":39},"HPO₄²⁻","Hydrogen phosphate ion","2.14 × 10⁻¹³","12.67",{"formula":91,"name":92,"type":36,"Ka":93,"pKa":94,"Kb":39,"pKb":39},"HOCl","Hypochlorous acid","3.5 × 10⁻⁸","7.46",{"formula":96,"name":97,"type":36,"Ka":98,"pKa":84,"Kb":39,"pKb":39},"HNO₂","Nitrous acid","7.24 × 10⁻⁴",{"formula":100,"name":101,"type":36,"Ka":102,"pKa":103,"Kb":39,"pKb":39},"H₃PO₄","Phosphoric acid","7.59 × 10⁻³","2.12",{"formula":105,"name":106,"type":107,"Ka":108,"pKa":109,"Kb":39,"pKb":39},"C₆H₈O₇","Citric acid","Polyprotic weak acid","7.41 × 10⁻⁴","3.13",{"formula":111,"name":112,"type":113,"Ka":114,"pKa":115,"Kb":39,"pKb":39},"NH₄⁺","Ammonium ion","Conjugate acid","5.56 × 10⁻¹⁰","9.25",{"formula":117,"name":118,"type":113,"Ka":119,"pKa":120,"Kb":39,"pKb":39},"CH₃NH₃⁺","Methylammonium ion","2.27 × 10⁻¹¹","10.64",{"formula":122,"name":123,"type":124,"Ka":39,"pKa":39,"Kb":37,"pKb":125},"NH₃","Ammonia","Weak base","4.74",{"formula":127,"name":128,"type":124,"Ka":39,"pKa":39,"Kb":129,"pKb":130},"(CH₃)₂NH","Dimethylamine","5.4 × 10⁻⁴","3.27",{"formula":132,"name":133,"type":124,"Ka":39,"pKa":39,"Kb":134,"pKb":135},"CH₃NH₂","Methylamine","4.4 × 10⁻⁴","3.36",{"formula":137,"name":138,"type":139,"Ka":39,"pKa":39,"Kb":114,"pKb":115},"CH₃COO⁻","Acetate ion","Conjugate base",{"formula":141,"name":142,"type":139,"Ka":39,"pKa":39,"Kb":143,"pKb":144},"C₆H₅COO⁻","Benzoate ion","1.54 × 10⁻¹⁰","9.81",{"formula":146,"name":147,"type":139,"Ka":39,"pKa":39,"Kb":148,"pKb":149},"CNO⁻","Cyanate ion","2.88 × 10⁻¹¹","10.54",{"formula":151,"name":152,"type":139,"Ka":39,"pKa":39,"Kb":153,"pKb":154},"CN⁻","Cyanide ion","2.04 × 10⁻⁵","4.69",{"formula":156,"name":157,"type":139,"Ka":39,"pKa":39,"Kb":158,"pKb":159},"FCH₂COO⁻","Fluoroacetate ion","3.89 × 10⁻¹²","11.41",{"formula":161,"name":162,"type":139,"Ka":39,"pKa":39,"Kb":163,"pKb":164},"HCOO⁻","Formate ion","5.65 × 10⁻¹¹","10.25",{"formula":166,"name":167,"type":139,"Ka":39,"pKa":39,"Kb":168,"pKb":169},"ClO⁻","Hypochlorite ion","2.86 × 10⁻⁷","6.54",{"formula":171,"name":172,"type":139,"Ka":39,"pKa":39,"Kb":173,"pKb":174},"NO₂⁻","Nitrite ion","1.38 × 10⁻¹¹","10.86",28,{"label":177},"ChemWhiz course-canonical acid-base constants (25 °C), aligned with modern general-chemistry conventions",[179,180,181,182],"All values at 25 °C (298.15 K). A dash means the constant is not tabulated for that species — derive it from the conjugate partner with Ka × Kb = Kw.","For a conjugate pair, pKa + pKb = pKw ≈ 14.00 at 25 °C (tabulated pairs may differ in the last digit from independent rounding).","Larger Ka (smaller pKa) = stronger weak acid; larger Kb (smaller pKb) = stronger weak base.","These are the course-canonical values: every ChemWhiz problem that needs one of these constants uses the value in this table.",[184,185,186,187,188],"acids-bases-and-ph","buffers-and-titration-curves","solubility-and-complex-ion-equilibria","chemical-equilibrium","entropy-and-free-energy",[],[191,192,193,194,195,196,197],"Ka values table","Kb values table","acid ionization constant","base ionization constant","pKa table","weak acid strength","conjugate acid base pair",1785108608443]