Vapor tension

Osmotic press data for solns of NC in acet have been obtained by Huggins(Ref 21), vapor tension s of gels by Schult2( Ref 15) and by Calvet(Ref 22), sedimentation rates by Moisimann et al (Refs 24 25), viscosity vs NC concn by Wissler (Ref 36), thermodynamic props by Munster (Ref 41), and various other props of NC-acet solns are discussed in Refs 13,23,26,29,32,34,35,38,39 44. The absorption spectra of acet are recorded by Pauling (Ref 30) and the reaction with 1,3,5-TNB, in the presence of an alkali, to give a black solid complex has been noted by Kimura (Ref 43)... 

We distinguish here a lower limit, which depends on the fuel deficiency, and an upper limit, which depends on oxygen deficiency in mixtures with an overabundance of fuel. For fluids we also give the temperature at which the saturating vapor tension becomes sufficient to form an explosive mixture at atmospheric pressure. 

The flegmatizing concentration exceeds the vapor tension of CCI4 at room ... 

Solvent. Water is the usual solvent, but because it evaporates very easily some workers (D15) have used glycerol or analogous substances to reduce the vapor tension. These, however, have higher viscosities than water and will affect the mobility u of the migrating particle according to the equation... 

The following experiments could not be carried out to the end of the reaction on account of the trifling vapor tension of the materials started with. 

It is believed that the water in the crystals called efflorescent tends to pass off into the atmosphere. This tendency resembles the tendency of water to evaporate. And like water, this water of crystallization passes off only when the vapor tension of the crystal exceeds the tension of the water vapor in the atmosphere. Thus sodium sulphate at ordinary temperatures has a greater vapor tension than the atmospheric water vapor, but gypsum (crystallized calcium sulphate) has a lower vapor tension than the atmospheric water vapor. Hence sodium sulphate effloresces, but calcium sulphate does not. This is an easy way to distinguish the two compounds. 

Discuss molecules and molecular weight in the light of the Laws of Avogadro and Gay-Lussac, vapor density, vapor tension, elevation of the boiling point, and depression of the freezing point. 

Take a glass tube about 90 cm. long and closed at one end, and dry and warm it. Fill it with dry, warm mercury and invert in a mortar containing the same liquid. The mercury will fall a little in the tube. Introduce a little water by means of a small pipette or by a medicine dropper, and the mercury will soon fall slightly, owing to the pressure of the water vapor — tension of aqueous vapor — in the space above the mercury. Warm the upper end of the tube with the hand or a lighted candle, and the mercury falls still lower. If it were possible to boil water in the tube, the pressure of the vapor would be equal to the pressure of the atmosphere at that instant, since water boils when it just overcomes atmospheric pres-... 

Would all liquids have the same vapor tension at a given temoer-ature ... 

Put with certain metallic chlorides ammonia gas is absorbed by these chlorides and forms with them definite solid compounds the dissociation of an ammonia chloride into a metallic chloride and ammonia gas corresponds to a curve of transformation tensions which is here called the curve of dissociation tensions, Isam-bert has determined a certain number of these curves and has shown their analogy to the curve fo. vapor tension of saturated vapors from liquids his work has since been completed by Joan-nis and Croizier. ... 

The curve of saturated vapor tensions from the liquid ... 

Lemoine having worked at 440 with commercial red phosphorus prepared between 250 and 300 , the vapor tension should have, as in Troost and Hautefeuille s experiments, increased rapidly up to the tension of saturated vapor from commercial red phosphorus, then decrease to the tension of saturated vapor of red phosphorus prepared at 440 . 

The liquid mixture whose composition is X and whose vapor tension II is in the presence of a saturated vapor of composition x the point n, of abscissa X and ordinate i7, associated with the point N of the same ordinate, concludes the representation of an equilib-... 

First Case.—During distillation the vapor tension constanOy... 

Second Case.—Whether the value of X which represents the initial composition of the liquid be less than or higher than y the vapor tension constantly decreases and approaches P the composition X of the liquid and the composition x of the vapor both vary in the same way and approach. When the vapor tension reaches the value P there is established a permanent regime of distillation the vapor tension changes no more the vapor distilled and the liquid not distilled conserve a constant composition f. This permanent regime is stable. 

In our second case, the mixture of concentration f which has, at the temperature considered, a definite vapor tension and passes over imaltered by distillation, may be confused with a definite compound this confusion may be readily obviated if it is noticed that the composition of the mixture having these properties depends on the temperature. 

The evaporation, at ordinaiy temperature, of an aqueous solution of hydrochloric acid always furnishes, after a certain time, a mixture of constant vapor tension and of constant composition, which Bineau had considered as a definite hydrate, represented... 

Three observations of vapor tensions, at different but known temperatures, allow determining the three constants m, n, 2 it is then easy to calculate the value of p that formula (6) gives corresponding to each value of the temperature T,/and to compare the numbers thus obtained with the results of observation. 

Sai/ts (theory of), double, 118 mixtures of, 259 solubility surface, 120 transformation point, 152 Saponihcation, 54 Saturation, of solution, 63 Solubility, and pressure, 200 curve, 216, 2, 240 of isomoiphous salts, 264 surface of, 120, 131 Solution, concentration of, 204, 216 freesing-point lowering, 203 saturation, 63, 196, 216 soUd, 156, 263, 301 supersaturated, 86 unsaturated, 217 vapor tension of, 204 Specific heat, of gs, 30-33 Surfusion, 164, 185... 

In order to determine the endpoint of the process, many procedures have been suggested, including pressure rise measurement, the Karl Fischer method, weight curves, vapor tension, moisture equilibration, nuclear magnetic resonance, and dielectric measurement. 

The true specific gravity is also of great value in theoretical studies for the observation of transformation points. Since fusion from the exact standpoint represents a change of state which may be located by the discontinuity of some physical property, it may represent the intersection of the vapor-tension curves of the crystalhne and... 

Crystals, mp 75-76. Technical grades may have almond-like odor, dj 1.4210, Vapor tension at 30 1.21 x 10 mm. uv max (95% ethanol) 262 nm Watson, Chem. < Ind. (London) 1956, 349. Soly in water < 1 5000, in ethanol about 2,9%, in kerosene 5 7.5%. Sol in acetone, benzene, toluene, xylene, peer ether. Resistant to acid and alkaline hydrolysis. Strong oxidizing agents convert it to the corresponding sulfoxide and sulfone. 

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