Vapor pressure-vapor composition curves of ideal solutions of two volatile, consolute liquids

1932 ◽  
Vol 9 (8) ◽  
pp. 1455
Author(s):  
H. S. van Klooster
Keyword(s):  
Vapor Pressure ◽  
Vapor Composition ◽  
Ideal Solutions

Ideal Solutions and Colligative Properties

2009 ◽  
Author(s):  
Christopher O. Oriakhi
Keyword(s):  
Vapor Pressure ◽  
Freezing Point ◽  
Pure Water ◽  
The Other ◽  
Dissolved Species ◽  
Pure Solvent ◽  
Ideal Solutions ◽  
Lower Vapor Pressure ◽  
Solution Changes ◽  
Colligative Properties

Colligative properties of solutions are those that depend only on the number of solute particles (molecules or ions) in the solution rather than on their chemical or physical properties. The colligative properties that can be measured experimentally include: • Vapor pressure depression • Boiling point elevation • Freezing point depression • Osmotic pressure Noncolligative properties, on the other hand, depend on the identity of the dissolved species and the solvent. Examples include solubility, surface tension, and viscosity. The addition of a solute to a solvent typically causes the vapor pressure of the solvent (above the resulting solution) to be lower than the vapor pressure above the pure solvent. As the concentration of the solute in the solution changes, so does the vapor pressure of the solvent above a solution. The vapor pressure of a solution of a nonvolatile solute is always lower than that of the pure solvent. For example, an aqueous solution of NaCl has a lower vapor pressure than pure water at the same temperature. The addition of solute to a pure solvent depresses the vapor pressure of the solvent. This observation, first made by Raoult, is now commonly known as Raoult’s law. The law states that the lowering of vapor pressure of a solution containing non-volatile solute is proportional to the mole fraction of the solute.

ChemInform Abstract: Vapor Composition and Vapor Pressure of ZnSe from a Modified Knudsen Technique Between 1190 and 1310 K.

ChemInform ◽  
2010 ◽  
Vol 28 (7) ◽  
pp. no-no
Author(s):  
E. SCHOENHERR ◽  
M. FREIBERG ◽  
D. SICHE ◽  
H. HARTMANN
Keyword(s):  
Vapor Pressure ◽  
Vapor Composition ◽  
Knudsen Technique

Standard States

1993 ◽  
Author(s):  
Greg M. Anderson ◽  
David A. Crerar
Keyword(s):  
Free Energy ◽  
Vapor Pressure ◽  
Reference State ◽  
Condensed Phases ◽  
Free Energies ◽  
State Variable ◽  
Ideal Solutions ◽  
Solid Liquid ◽  
Pure Constituent

At this point we have introduced the activity as a ratio of fugacities (Chapter 11). The fugacity of a constituent, in turn, we saw was a quantity very much like a vapor pressure or partial pressure, which is directly linked to the Gibbs free energy of that constituent, such that a ratio of fugacities leads directly to a difference in free energies. The fugacity was introduced as a means of dealing with gases and gaseous solutions, and it is measured by measuring gas volumes or densities. Nevertheless, there is nothing restricting its use to gaseous constituents, and we suggested that it is very useful to regard the fugacity as a state variable; as a property of any constituent of any system, solid, liquid, or gas, whether equilibrated with a gas or not, and whether measurable or not. This leads to the easiest approach to understanding activities. The activity of a constituent is the ratio of the fugacity of that constituent to its fugacity in some other state, which we called a reference state. We then showed through consideration of the Lewis Fugacity Rule, which is an extension of Dalton's Law, that for ideal solutions of condensed phases, the activity of a constituent equals its mole fraction, if the reference state is the pure constituent at the same P and T. Deviations from ideal behaviour are then conveniently handled by introducing Henryan and Raoultian activity coefficients. The utility of these relations would be quite sufficient for retaining the activity in our collection of thermodynamic parameters, but in fact the activity can be applied to a much wider range of conditions, simply by varying the choice of reference state. We now examine the various possible choices of this reference state, and the resulting equations and applications. In the most general sense, the fugacity and activity concepts satisfy the need to relate system compositions to free energy changes. That a single parameter, the activity, can do this for essentially any system is a tribute to its tremendous versatility.

Vapor pressure and vapor composition of diethylgallium chloride and diethylaluminum chloride

1991 ◽  
Vol 36 (4) ◽  
pp. 372-374 ◽  
Author(s):  
Nicholas I. Buchan ◽  
Robert M. Potemski ◽  
Thomas F. Kuech
Keyword(s):  
Vapor Pressure ◽  
Vapor Composition
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