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The non-random two-liquid model [1] (abbreviated NRTL model) is an activity coefficient model introduced by Renon and Prausnitz in 1968 that correlates the activity coefficients of a compound with its mole fractions in the liquid phase concerned. It is frequently applied in the field of chemical engineering to calculate phase equilibria.
However, the initial statuses can be different. In a dissolution process, a solute is changed from a pure phase—solid, liquid, or gas—to a solution phase. If the pure phase of the solute is a solid or gas (presuming the solvent itself is liquid), the process can be seen in two stages: the phase change into a liquid, and the mixing of liquids.
Although, thorough mixing of gases and vapors may not be as easily accomplished. [citation needed] For example, if there are 10 grams of salt (the solute) dissolved in 1 litre of water (the solvent), this solution has a certain salt concentration . If one adds 1 litre of water to this solution, the salt concentration is reduced.
The enthalpy of mixing is zero [2] as is the volume change on mixing by definition; the closer to zero the enthalpy of mixing is, the more "ideal" the behavior of the solution becomes. The vapor pressures of the solvent and solute obey Raoult's law and Henry's law , respectively, [ 3 ] and the activity coefficient (which measures deviation from ...
Gas blending is the process of mixing gases for a specific purpose where the composition of the resulting mixture is defined, and therefore, controlled. A wide range of applications include scientific and industrial processes, food production and storage and breathing gases.
In chemistry and physics, the dimensionless mixing ratio is the abundance of one component of a mixture relative to that of all other components. The term can refer either to mole ratio (see concentration ) or mass ratio (see stoichiometry ).
[8] [9] Mixtures differ from chemical compounds in the following ways: The substances in a mixture can be separated using physical methods such as filtration, freezing, and distillation. There is little or no energy change when a mixture forms (see Enthalpy of mixing). The substances in a mixture keep their separate properties.
As such, enthalpy of mixing tends to be determined experimentally in order to calculate entropy of mixing, rather than the reverse. Enthalpy of mixing is defined exclusively for the continuum regime, which excludes molecular-scale effects (However, first-principles calculations have been made for some metal-alloy systems such as Al-Co-Cr [ 4 ...