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Evaporation is a phase transition from the liquid phase to vapor (a state of substance below critical temperature) that occurs at temperatures below the boiling temperature at a given pressure. Evaporation occurs on the surface. Evaporation only occurs when the partial pressure of vapor of a substance is less than the equilibrium vapor pressure ...
In thermodynamics, Trouton's rule states that the (molar) entropy of vaporization is almost the same value, about 85–88 J/(K·mol), for various kinds of liquids at their boiling points. [1] The entropy of vaporization is defined as the ratio between the enthalpy of vaporization and the boiling temperature.
Temperature-dependency of the heats of vaporization for water, methanol, benzene, and acetone. In thermodynamics, the enthalpy of vaporization (symbol ∆H vap), also known as the (latent) heat of vaporization or heat of evaporation, is the amount of energy that must be added to a liquid substance to transform a quantity of that substance into a gas.
The atmospheric pressure boiling point of a liquid (also known as the normal boiling point) is the temperature at which the vapor pressure equals the ambient atmospheric pressure. With any incremental increase in that temperature, the vapor pressure becomes sufficient to overcome atmospheric pressure and cause the liquid to form vapor bubbles.
Boiling and evaporation are the two main forms of liquid vapourization. There are two main types of boiling: nucleate boiling where small bubbles of vapour form at discrete points, and critical heat flux boiling where the boiling surface is heated above a certain critical temperature and a film of vapour forms on the surface.
Demonstration of evaporative cooling. When the sensor is dipped in ethanol and then taken out to evaporate, the instrument shows progressively lower temperature as the ethanol evaporates. Rain evaporating after falling on hot pavement. Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. [1]
At this pressure, the condensation temperature of the water vapor at the heat exchanger will be 390 K. Taking into account the boiling point elevation of the salt water we wish to evaporate (8 K for a saturated salt solution), this leaves a temperature difference of less than 8 K at the heat exchanger. A small ∆T leads to slow heat transfer ...
Dühring's plot for boiling point of NaCl solutions [1] Dühring's rule is a scientific rule developed by Eugen Dühring which states that a linear relationship exists between the temperatures at which two solutions exert the same vapour pressure. [1] [2] The rule is often used to compare a pure liquid and a solution at a given concentration.