Enthalpy changes on mixing of liquids

Mixing of two or more chemicals which have dissimilar molecular structures may be 

Every gas has a critical temperature above which it cannot be liquefied by the application 

If the temperature remains constant, the pressure within any cylinder containing liquefied gas will remain constant as gas is drawn off (i.e. more liquid simply evaporates) so the quantity of gas remaining cannot be deduced from the pressure. 

Cas Boiling point Liquid density Volume ratio of gas Vapour Critical 

The rate of chemical reaction is generally a function of reactant concentration and temperature. For many homogeneous reactions therefore, if they are exothermic, 

Mixing of two or more ehemieals whieh have dissimilar moleeular stmetures may be exothermie (liberating heat) or endothermie (absorbing heat). As a result  

Every gas has a eritieal temperature above whieh it eannot be liquefied by the applieation of pressure alone. The eritieal pressure is that required to liquefy a gas at its eritieal temperature. Data for eommon gases are given in Table 4.5. As a eonsequenee  

Liquefied gases may be stored fully refrigerated, with the liquid at its bubble point at near atmospherie pressure fully pressurized, i.e. at ambient temperature or semi-refrigerated with the temperature below ambient but the vapour pressure above atmospherie pressure. Of the gases listed in Table 4.6, all those with eritieal temperatures below ambient must be maintained under refrigeration to keep them in the liquid phase. 

Gas Boiling point at 1 bar abs. (°C) Liquid density at boiling point (kg/mh Volume ratio gas (1 bar abs., 20°C) to liquid (at boiling point) Vapour pressure at 38°C (bar abs.) Critical temperature (°C) 

Temperature control Adequately sized pressure relief 

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Ahm = enthalpy change on mixing pure liquids to give 1 mol of desired composition... 

In most common chemical reactions, one or more of the reactants is in solution. Thus, an easy method to determine thermodynamic quantities of solution is desirable. Enthalpy of solution (heat of solution) is defined as the change in the quantity of heat which occurs due to a combination of a particular solute (gas, liquid, or solid) with a specified amount of solvent to form a solution. If the solution consists of two liquids, the enthalpy change upon mixing the separate liquids is called the heat of mixing. When additional solvent is added to the solution to form a solution of lower solute concentration, the heat effect is called the heat of dilution. The definitions of free energy of solution, entropy of solution, and so on follow the pattern of definitions above. 

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