[{"data":1,"prerenderedAt":96},["ShallowReactive",2],{"reference-colligative-constants":3},{"table":4},{"id":5,"slug":6,"title":7,"shortTitle":8,"category":9,"description":10,"metaDescription":11,"columns":12,"rows":28,"entryCount":67,"sources":68,"notes":76,"relatedTopics":82,"relatedElements":84,"seoKeywords":85,"tableTitle":93,"tableDescription":94,"seoTitle":95},14,"colligative-constants","Boiling-Point Elevation and Freezing-Point Depression Constants","Kb / Kf (molal)","solutions","Molal boiling-point-elevation (Kb) and freezing-point-depression (Kf) constants for common solvents. Use ΔTb = i·Kb·m and ΔTf = i·Kf·m, where m is the molality of the solution and i is the van 't Hoff factor.","Molal boiling-point-elevation (Kb) and freezing-point-depression (Kf) constants for common solvents, for the colligative ΔT = i·K·m calculations.",[13,17,21,25],{"key":14,"label":15,"type":16},"solvent","Solvent","text",{"key":18,"label":19,"type":20},"formula","Formula","chem",{"key":22,"label":23,"type":16,"sortType":24},"Kb","Kb (bp elevation)","numeric",{"key":26,"label":27,"type":16,"sortType":24},"Kf","Kf (fp depression)",[29,34,39,44,49,54,59,63],{"solvent":30,"formula":31,"Kb":32,"Kf":33},"Water","H₂O","0.512 °C·kg/mol","1.86 °C·kg/mol",{"solvent":35,"formula":36,"Kb":37,"Kf":38},"Acetic acid","CH₃COOH","3.07 °C·kg/mol","3.9 °C·kg/mol",{"solvent":40,"formula":41,"Kb":42,"Kf":43},"Benzene","C₆H₆","2.53 °C·kg/mol","5.12 °C·kg/mol",{"solvent":45,"formula":46,"Kb":47,"Kf":48},"Chloroform","CHCl₃","3.63 °C·kg/mol","4.68 °C·kg/mol",{"solvent":50,"formula":51,"Kb":52,"Kf":53},"Nitrobenzene","C₆H₅NO₂","5.24 °C·kg/mol","8.1 °C·kg/mol",{"solvent":55,"formula":56,"Kb":57,"Kf":58},"Ethanol","C₂H₅OH","1.20 °C·kg/mol","—",{"solvent":60,"formula":61,"Kb":62,"Kf":58},"Carbon disulfide","CS₂","2.34 °C·kg/mol",{"solvent":64,"formula":65,"Kb":58,"Kf":66},"Camphor","C₁₀H₁₆O","37.7 °C·kg/mol",8,[69,73],{"label":70,"url":71,"covers":72},"OpenStax Chemistry 2e, Section 11.4, Table 11.2","https://openstax.org/books/chemistry-2e/pages/11-4-colligative-properties","water, acetic acid, benzene, chloroform, and nitrobenzene",{"label":74,"covers":75},"ChemWhiz course constants","ethanol, carbon disulfide, and camphor",[77,78,79,80,81],"ΔTb = i·Kb·m raises the boiling point; ΔTf = i·Kf·m lowers the freezing point. Both use MOLALITY (mol solute per kg solvent), not molarity.","The van 't Hoff factor i counts dissolved particles: i = 1 for nonelectrolytes, i ≈ the ion count for strong electrolytes (e.g. i ≈ 2 for NaCl, i ≈ 3 for CaCl₂).","A dash means that constant is not commonly tabulated for that solvent.","Camphor's very large Kf made it the classic solvent for molar-mass determination by freezing-point depression (the Rast method).","ChemWhiz uses this one consistent value set across the site.",[83],"colligative-properties",[],[86,87,88,89,90,91,92],"boiling point elevation constant","freezing point depression constant","molal Kb Kf table","ebullioscopic constant","cryoscopic constant","colligative properties","van t Hoff factor","Molal Kb and Kf Constants","Apply ΔT = i·K·m for boiling-point elevation (Kb) and freezing-point depression (Kf).","Boiling-Point and Freezing-Point Constants",1787246032701]