Search results
Results from the WOW.Com Content Network
With the formula below, freezing-point depression can be used to measure the degree of dissociation or the molar mass of the solute. This kind of measurement is called cryoscopy ( Greek cryo = cold, scopos = observe; "observe the cold" [ 7 ] ) and relies on exact measurement of the freezing point.
A 1:1 dilution with water is usually used, resulting in a freezing point of about −34 °F (−37 °C), depending on the formulation. In warmer or colder areas, weaker or stronger dilutions are used, respectively, but a range of 40%/60% to 60%/40% is frequently specified to ensure corrosion protection, and 70%/30% for maximum freeze prevention ...
The term "cryoscopy" means "freezing measurement" in Greek. Freezing point depression is a colligative property, so ΔT depends only on the number of solute particles dissolved, not the nature of those particles. Cryoscopy is related to ebullioscopy, which determines the same value from the ebullioscopic constant (of boiling point elevation).
This Wikipedia page provides a comprehensive list of boiling and freezing points for various solvents.
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.
Std entropy change of vaporization, Δ vap S o: 109.67 J/(mol·K) Molal freezing point constant: −1.99 °C kg/mol Solid properties Std enthalpy change of formation, Δ f H o solid: −277.7 kJ/mol Standard molar entropy, S o solid: 160.7 J/(mol K) [5] Heat capacity, c p: 111.46 J/(mol K) [5] Liquid properties Std enthalpy change of formation ...
This energy includes the contribution required to make room for any associated change in volume by displacing its environment against ambient pressure. The temperature at which the phase transition occurs is the melting point or the freezing point, according to context. By convention, the pressure is assumed to be 1 atm (101.325 kPa) unless ...
Critical point: 554 K (281 °C), 4070 kPa Std enthalpy change of fusion, Δ fus H o: 2.68 kJ/mol crystal I → liquid Std entropy change of fusion, Δ fus S o: 9.57 J/(mol·K) crystal I → liquid Std enthalpy change of vaporization, Δ vap H o: 32 kJ/mol Std entropy change of vaporization, Δ vap S o: 111.80 J/(mol·K) Solid properties Std ...