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In thermodynamics, the cryoscopic constant, Kf, relates molality to freezing point depression (which is a colligative property). It is the ratio of the latter to the former: b is the molality of the solution. Through cryoscopy, a known constant can be used to calculate an unknown molar mass. The term "cryoscopy" means "freezing measurement" in ...
Freezing point depression is responsible for keeping ice cream soft below 0°C. [1] Freezing-point depression is a drop in the maximum temperature at which a substance freezes, caused when a smaller amount of another, non- volatile substance is added. Examples include adding salt into water (used in ice cream makers and for de-icing roads ...
Colligative properties. In chemistry, colligative properties are those properties of solutions that depend on the ratio of the number of solute particles to the number of solvent particles in a solution, and not on the nature of the chemical species present. [1] The number ratio can be related to the various units for concentration of a ...
Through the procedure called ebullioscopy, a known constant can be used to calculate an unknown molar mass. The term ebullioscopy means "boiling measurement" in Latin. This is related to cryoscopy, which determines the same value from the cryoscopic constant (of freezing point depression). This property of elevation of boiling point is a ...
K b, the ebullioscopic constant, which is dependent on the properties of the solvent. It can be calculated as K b = RT b 2 M/ΔH v, where R is the gas constant, and T b is the boiling temperature of the pure solvent [in K], M is the molar mass of the solvent, and ΔH v is the heat of vaporization per mole of the solvent.
The freezing point of a solution is lower than that of the pure solvent, and the freezing-point depression (ΔT) is directly proportional to the amount concentration for dilute solutions. When the composition is expressed as a molality , the proportionality constant is known as the cryoscopic constant ( K f ) and is characteristic for each solvent.
The van 't Hoff factor i (named after Dutch chemist Jacobus Henricus van 't Hoff) is a measure of the effect of a solute on colligative properties such as osmotic pressure, relative lowering in vapor pressure, boiling-point elevation and freezing-point depression. The van 't Hoff factor is the ratio between the actual concentration of particles ...
Molar heat capacity. The molar heat capacity of a chemical substance is the amount of energy that must be added, in the form of heat, to one mole of the substance in order to cause an increase of one unit in its temperature. Alternatively, it is the heat capacity of a sample of the substance divided by the amount of substance of the sample; or ...