scholarly journals On the vapour-pressure and osmotic pressure of a volatile solute

1908 ◽  
Vol 81 (548) ◽  
pp. 336-336 ◽  
Keyword(s):  
Liquid Phase ◽  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Specific Volume ◽  
Vapour Phase ◽  
The Other ◽  
Other Hand ◽  
Specific Volumes

It follows by a method given in a recent paper by the author that if the osmotic membrane be assumed to be impermeable to the solute, the formula for the change of vapour-pressure of a volatile solute with hydrostatic pressure, and also the formula for the osmotic pressure which is deduced from it, must be the same as the formula for a non-volatile solute, and should not contain any terms depending on the vapour-pressure of the solute, except in so far as it may affect the hydrostatic pressure of the solution. If, on the other hand, an osmotic membrane is regarded as a vapour-sieve permeable to the vapour of the solution but not to the liquid phase, the equation takes a different form, depending on the concentration of the constituents in the vapour-phase. If c 1 , c 2 , etc., be the concentrations of the constituents in grammes per gramme of the vapour, and if U 1 , U 2 , etc., be the specific volumes of the constituents in the solution, the change of total vapour-pressure dp of the solution for a change of hydrostatic pressure d P is given by the relation, ∑ c U d P = v dp , where v is the specific volume of the whole vapour-phase. If only on constituent is volatile, this relation reduces to the form U d P = v dp for that constituent.

scholarly journals The Teaching of Specific Volume and Density

1910 ◽  
Vol 5 (89) ◽  
pp. 356-357
Author(s):  
F. G. Daniell
Keyword(s):  
Science Teachers ◽  
Specific Volume ◽  
The Other ◽  
Density Determination ◽  
Other Hand ◽  
Correct Definition ◽  
Subsequent Discussion ◽  
The Subject ◽  
Specific Volumes

The purpose of the author was to urge that specific volume should precede density, because (1) the idea of specific volume is more important and fruitful than the idea of density; (2) the notion of specific volume is easier to acquire. Dealing first with the second reason, evidence was quoted from experienced science teachers and examiners to the effect that boys frequently failed to grasp the idea of density although they could formulate a correct definition, and carry out and describe a density determination with unimpeachable correctness. On the other hand the author had found that the idea of density had been readily acquired where the class had approached the subject through a preliminary lesson on specific volume. A short demonstration was then given of a method by which the relative specific volumes of substances or their comparative “roominess” (Raümigkeit), i.e. the volume occupied by 1 lb. of each, could be readily and effectively brought home to the class. (In subsequent discussion the chairman suggested the word ‘roomage’ in place of specific volume.)

scholarly journals Note on osmotic pressure

1914 ◽  
Vol 90 (615) ◽  
pp. 41-45
Keyword(s):  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Numerical Data ◽  
The Other ◽  
Present Moment ◽  
Capillary Surface ◽  
Pure Solvent ◽  
Definition Of ◽  
Complete Account ◽  
Strict Definition

The vapour pressure theory regards osmotic pressure as the pressure required to produce equilibrium between the pure solvent and the solution. Pressure applied to a solution increases its internal vapour pressure. If the compressed solution be on one aide of a semi-permeable partition and the pure solvent on the other, there is osmotic equilibrium when the com-pression of the solution brings its vapour pressure to equality with that of the solvent. So long ago as 1894 Ramsay* found that with a partition of palladium, permeable to hydrogen but not to nitrogen, the hydrogen pressures on each side tended to equality, notwithstanding the presence of nitrogen under pressure on one side, which it might have been supposed would have resisted tin- transpiration of the hydrogen. The bearing of this experiment on the problem of osmotic pressure was recognised by van’t Hoff, who observes that "it is very instructive as regards the means by which osmotic pressure is produced." But it was not till 1908 that the vapour pressure theory of osmotic pressure was developed on a finu foundation by Calendar. He demonstrated, by the method of the "vapour sieve" piston, the proposition that “any two solutions in equilibrium through any kind of membrane or capillary surface must have the same vapour pressures in respect of each of their constituents which is capable of diffusing through their surface of separation"—a generalisation of great importance for the theory of solutions. Findlay, in his admirable monograph, gives a very complete account of the contending theories of osmotic pressure, a review of which leaves no doubt that at the present moment the vapour pressure theory stands without a serious rival Some confusion of ideas still arises from the want of adherence to a strict definition of osmotic pressure to which numerical data from experimental measurements should he reduced. Tire following definitions appear to be tire outcome of tire vapour pressure theory :— Definition I.—The vapour pressure of a solution is the pressure of the vapour with which it is in equilibrium when under pressure of its own vapour only.

scholarly journals OSMOTIC PRESSURE STUDY OF PROTEIN FRACTIONS IN NORMAL AND IN NEPHROTIC SUBJECTS

1939 ◽  
Vol 69 (6) ◽  
pp. 819-831 ◽  
Author(s):  
Jaques Bourdillon
Keyword(s):  
Osmotic Pressure ◽  
Normal Serum ◽  
The Other ◽  
Protein Fractions ◽  
Molecular Weights ◽  
Other Hand ◽  
Normal Albumin

In serum of patients with nephrosis both albumin and globulin showed by osmotic pressure nearly double the molecular weights of normal albumin and globulin. In the urines of such patients, on the other hand, both proteins showed molecular weights lower even than in normal serum. The colloidal osmotic pressures were measured by the author's method at such dilutions that the van't Hoff law relating pressures to molecular concentrations could be directly applied. For the albumin and globulin of normal serum the molecular weights found were 72,000 and 164,000 respectively, in agreement with the weights obtained by other methods.

scholarly journals The relation between the osmotic pressure and the vapour pressure in a concentrated solution

1906 ◽  
Vol 77 (516) ◽  
pp. 234-240 ◽  
Keyword(s):  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Specific Volume ◽  
Hydrostatic Equilibrium ◽  
Liquid Column ◽  
Permeable Membrane ◽  
Pure Solvent ◽  
Concentrated Solution

1. The relation between the vapour pressure and the osmotic pressure of a solution is often investigated by considering the equilibrium of a column of solution separated at the bottom from the pure solvent by a semi-permeable membrane, and placed in an atmosphere of vapour from the solvent. Now the hydrostatic equilibrium of the vapour column gives δp = gs -1 δh , where p is the vapour pressure of the pure solvent, g the acceleration due to gravity, h the height above the surface of the pure solvent, and s the specific volume of the vapour. Hence considering the equilibrium of the liquid column we get P + p - p' = ρhg = ρ ∫ p p' sdp , when P is the osmotic pressure, p' the vapour pressure of the solution, p that of the pure solvent, and where ρ is the effective mean density of the column of liquid.

Borierungsreaktionen an den N-Oxiden und -Iminen ungesättigter Stickstoffbasen / Boration Reactions with the N-Oxides and m-Imines of Unsaturated Nitrogen Bases

1980 ◽  
Vol 35 (5) ◽  
pp. 568-577 ◽  
Author(s):  
Peter Paetzold ◽  
Günther Schimmel
Keyword(s):  
Nitrous Oxide ◽  
Liquid Phase ◽  
Gas Phase ◽  
The Other ◽  
Double Bonds ◽  
Similar Reduction ◽  
Nitrogen Bases ◽  
Other Hand

1,3-Dipolar reagents with an unsaturated CNO- or CNN-skeleton undergo 1,3-organoboration by triorganoboranes. On the other hand, the unsaturated NNO-skeletons in azoxybenzene or nitrous-oxide are reduced to the corresponding NN-fragment by trialkylboranes. The 1,3-addition of aminoborane Cl2BNMe2 to the aldimineoxide PhHC = NMe-0 represents one of the rare examples of analogous reactivity of BN- and CC-double bonds. O-Borylhydroxylamines PhHCR-NMe-OBR2 are reduced by BR′3 to PhHCR-NMe-BR′2 and R′0-BR2. Similar reduction products are isolated from liquid-phase thermolysis of PhHCEt-NMe-OBEt2 (16), whereas gas-phase thermolysis of 16 gives PhCH = NMe, (EtBO)3, and C4H10.

The Mechanism of Urine Formation in Invertebrates

1937 ◽  
Vol 14 (1) ◽  
pp. 20-34 ◽  
Author(s):  
L. E. R. PICKEN
Keyword(s):  
Sodium Chloride ◽  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Average Rate ◽  
Colloid Osmotic Pressure ◽  
Pericardial Fluid ◽  
Anodonta Cygnea ◽  
Cent Sodium ◽  
Urine Formation

1. In Anodonta cygnea: (a) The blood has a vapour pressure equivalent to that of a solution of ca. 0.10 per cent sodium chloride. (b) The pericardial fluid is isotonic with the blood. (c) The urine has a vapour pressure equivalent to that of a solution of ca. 0.06 per cent sodium chloride. (d) The hydrostatic pressure of the blood is ca. 6 cm. of water. (e) The calculated colloid osmotic pressure is ca. 3.8 mm. of water. (f) The average rate of filtration of fluid into the pericardium is ca. 250 c.c. in 24 hours. (g) The salt uptake from ingested phytoplankton is estimated as equivalent to 0.012. g. sodium chloride in 24 hours. (h) The loss of osmotically active substance in the urine is estimated as equivalent to 0.15 g. sodium chloride in 24 hours. 2. In Limnaea peregra the vapour pressure of the blood is equivalent to that of a solution of ca. 0.43 per cent sodium chloride. The pericardial fluid is isotonic with the blood, and the urine has a concentration equivalent to ca. 0.30 per cent sodium chloride. 3. In Limnaea stagnalis the hydrostatic pressure of the blood is ca. 8 cm. of water. The colloid osmotic pressure of the blood is ca. 2.5 cm. of water (calculated); that of the pericardial fluid is ca. 0.7 cm. of water.

Contributions of biofilm versus suspended bacteria in an aerobic circulating-bed biofilm reactor

2001 ◽  
Vol 43 (1) ◽  
pp. 303-310 ◽  
Author(s):  
H. Yu ◽  
B. J. Kim ◽  
B. E. Rittman
Keyword(s):  
Liquid Phase ◽  
Biofilm Reactor ◽  
The Other ◽  
Bulk Liquid ◽  
Diffusion Resistance ◽  
Diffusion Limitation ◽  
Toluene Concentration ◽  
Other Hand ◽  
Degradation Reaction

This study demonstrated that, during the two-step biodegradation of toluene in an aerobic circulating-bed biofilm reactor, biofilm and suspended bacteria played critical roles. Although the suspended bacteria were less than 1% of the total amount of biomass in the system, they transformed up to 30% of the toluene into its intermediate in the bulk liquid phase. On the other hand, most of the toluene intermediate was removed inside the biofilm, where diffusion resistance reduced the toluene concentration, thereby relieving inhibition to the degradation reaction of the intermediate. The suspended bacteria are most important for rapidly biodegraded substrates, for which diffusion limitation controls the kinetics in the biofilm. They lose importance when the effects of an inhibiting substrate must be overcome.

Influence of Liquid Phase on Grain Growth of Ba0.998La0.002TiO3 Ceramics

2008 ◽  
Vol 368-372 ◽  
pp. 461-464
Author(s):  
Yong Ping Pu ◽  
Gong An Yang ◽  
Yun He Liang ◽  
Wen Hu Yang ◽  
Jin Fei Wang
Keyword(s):  
Liquid Phase ◽  
Grain Growth ◽  
The Other ◽  
Other Hand ◽  
Liquid Phases

The influence of liquid phase on grain growth of Ba0.998La0.002TiO3+xmol%TiO2 (x=0~5.0) ceramics sintered at 1350°C was investigated. The result showed that the liquid phase must present during grain growth; on the other hand, BaTiO3 grains must be dissolved, and then, precipitated from the liquid phase during the process of dissolution-precipitation. Otherwise, the grain growth was inhibited. The liquid phases of Ba6Ti17O4 and Ba2TiSi2O8 promoted grain growth due to high solution of BaTiO3 grains in the liquid phases. Ba2Ti2SiP2O13 liquid phase inhibited grain growth since BaTiO3 grains cannot dissolve into the phase, consequently the samples showed insulating behaviour.

scholarly journals The osmotic pressure of compressible solutions of any degree of concentration

1907 ◽  
Vol 79 (533) ◽  
pp. 519-528 ◽  
Keyword(s):  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Concentrated Solutions ◽  
Insufficient Attention ◽  
Pure Solvent ◽  
The Subject ◽  
Great Simplicity ◽  
Made In

This paper is an attempt to make more complete the theory of solutions, at the same time maintaining as great simplicity of treatment as is possible without sacrificing precision. Renewed attention has been called to the subject, owing to the success of the experiments of the Earl of Berkeley and Mr. E. J. Hartley on the osmotic pressure of concentrated solutions of sugars. Diversity of opinion has existed in regard to the interpretation of these experiments, insufficient attention having been previously paid to the influence of the hydrostatic pressure of the pure solvent upon the value of the osmotic pressure. The principal advances made in this paper consist in simply demonstrating the influence of pressure upon osmotic pressure for compressible solutions and in including the effect of the variability of vapour pressure with hydrostatic pressure. The influences of accidental properties (such as the effects of gravitation) are excluded. Summary of Notation . The following is the notation employed. All the values are isothermal values. Solution .— Hydrostatic pressure ................................................................ p Vapour pressure corresponding to hydrostatic pressure p .. π p Vapour pressure when solution is in contact with its own vapour alone.............................................. π π Volume at hydrostatic pressure p .......................................... V p Reduction of volume when 1 gramme of solvent escapes....... s p Osmotic pressure for hydrostatic pressure p ........................... P p Osmotic pressure for hydrostatic pressure π π ....................... P π

Statistical Mechanics of Deuterium Exchange Reactions: Recalculation of Thermodynamic Properties of Water-Methanol Reactions

1979 ◽  
Vol 32 (3) ◽  
pp. 465 ◽  
Author(s):  
JR Khurma ◽  
DV Fenby
Keyword(s):  
Liquid Phase ◽  
Thermodynamic Properties ◽  
Force Field ◽  
Gas Phase ◽  
Vapour Pressure ◽  
The Other ◽  
Exchange Reactions ◽  
Statistical Mechanical ◽  
Experimental Values ◽  
Methanol Reactions

Thermodynamic properties of the reactions CH3OH+HDO → CH3D+H2O CH3OH+D2O → CH3OD+HDO in the gas phase are calculated from statistical mechanical equations. Two sets of calculated harmonic frequencies are used: one obtained from an experimental force field and the other from an ab initio force field. Thermodynamic properties of the corresponding liquid-phase reactions are obtained by combining the gas-phase values with vapour-pressure isotope effect results. The calculated properties are compared with published experimental values.

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