XI. Contributions to our knowledge of antimony pentachloride

1887 ◽  
Vol 42 (251-257) ◽  
pp. 379-387
Keyword(s):  
Boiling Point ◽  
Simple Formula ◽  
Fundamental Importance ◽  
Antimony Pentachloride ◽  
Vapour Density

Some months ago we showed that antimony pentachloride can be distilled, undecomposed, under much diminished pressure; our next step was the attempt to determine the vapour-density under similar conditions. The fact that the boiling point of antimony pentachloride lies much lower than that of the trichloride would seem to show that the vapour-density of the pentachloride, as in the case of the trichloride, corresponds to the simpler formula. Nevertheless, on account of the fundamental importance which the establishment of the simple formula SbCl 5 would have for the valence of antimony, it seemed indispensably necessary to make a determination of the vapour-density.

scholarly journals The constitution of sulphur vapour

1919 ◽  
Vol 95 (672) ◽  
pp. 484-492 ◽  
Keyword(s):  
Boiling Point ◽  
Diatomic Molecules ◽  
Conclusive Evidence ◽  
The Other ◽  
Molecular Formula ◽  
Reduced Pressure ◽  
Vapour Density ◽  
Temperature And Pressure ◽  
Sulphur Vapour

The constitution of sulphur vapour has been studied by many investigators, the method usually employed being based upon the determination of the density. In 1835 Dumas and Mitscherlich found the vapour density at temperatures near the boiling point to be 6∙56, which corresponds closely with the molecular formula S 6 . Deville and Troost carried out determinations at temperatures ranging from 860°C to 1040°C. and obtained the value 2∙23 which is that required by the formula S 2 . More recently Biltz has shown that below 800°C. the density is greater than is required by the formula S 2 , and at 468°C. becomes 7∙8 which corresponds approximately to the formula S 7 , without any constant value being observed between these temperatures. Bleier and Kohn found that when determinations were made under reduced pressure between 192°C. and 310°C. the density of the vapour gradually rose with increase of pressure and slowly but asymptotically approached the value S 8 . Evidence of the existence of molecules containing eight atoms has also been obtained from an examination of solutions of sulphur. Biltz holds that the value obtained by Dumas and Mitscherlich is only of significance for the conditions of temperature and pressure under which it was determined, and affords no evidence of the presence of hexatomic molecules in the vapour. His view is that only octatomic and diatomic molecules have any existence, the former gradually dissociating into the latter as the temperature is raised until about 900° C., the dissociation of the heavier molecules is complete and the vapour is composed entirely of diatomic molecules. Above this temperature no further change appears to occur. Premier, on the other hand, from a study of the curve representing the change of density with change of pressure considers that it is not unlikely that hexatomic and tetratomic molecules are formed as intermediate pro­ducts of the dissociation of the octatomic molecules. Of this, however, the investigation of the vapour density does not afford any conclusive evidence.

scholarly journals XII. Notes of researches on the poly-ammonias. — No. XIV. Diagnosis of diamines

1862 ◽  
Vol 11 ◽  
pp. 278-281
Keyword(s):  
Boiling Point ◽  
Valuable Data ◽  
Vapour Density ◽  
Satisfactory Manner

In former parts of this inquiry I have had repeated opportunities of discussing the features of distinction between the monamines and diamines. I have shown that the study of the genesis and of the transformations of an ammonia, and the observation of its boiling-point supply most valuable data for the elucidation of this question; and that the most reliable inferences may be drawn from the determination of its vapour-density. In continuing my experiments upon this subject, I have been led to the discovery of a class of salts, the formation of which decides the question in an equally satisfactory manner.

scholarly journals 3. On the Constitution of the Essential Oil of Cajeput

1862 ◽  
Vol 4 ◽  
pp. 326-327
Author(s):  
Maximilian Schmidl
Keyword(s):  
Essential Oil ◽  
Phosphoric Acid ◽  
Heavy Oil ◽  
Boiling Point ◽  
Lemon Yellow ◽  
Yellow Colour ◽  
Vapour Density

The author shows, that oil of cajeput is a mixture of an oil boiling about 175° Cent., and one or more oils of higher boiling point. In the present paper he investigates the first of those substances. When purified by repeated distillation, it is a colourless, limpid fluid, which by analysis and determination of its vapour density, is shown to have the formula C20 H16 + 2HO. When treated with anhydrous phosphoric acid, it is decomposed, and yields a mixture of three different hydrocarbons, to which the author gives the names of Cajputene, Isocajputene, and Metacajputene. The two former, though differing in properties, have both the formula C20 H16. The last, which is a very heavy oil, with a lemon yellow colour and brilliant fluorescence, is C40 H32.

2. On Zinc-Methyl

1862 ◽  
Vol 4 ◽  
pp. 315-317
Author(s):  
J. A. Wanklyn
Keyword(s):  
High Temperature ◽  
Specific Gravity ◽  
Boiling Point ◽  
The Body ◽  
Small Glass ◽  
Vapour Density ◽  
Glass Tubes

Considerable difficulties attend the preparation of zinc-methyl. Frankland, who discovered the body, obtained it by heating pure iodide of methyl and zinc enclosed in small glass tubes. Owing to the high temperature at which reaction takes place, much gas is formed; hence the operation must be confined to very small quantities of materials.No determination of the boiling-point, specific gravity, nor yet of the vapour density of zinc-methyl, was made by its discoverer; from which fact may be inferred how small was the product available for investigation.

scholarly journals XVII. On the atomic weight of glucinum (Beryllium)

1883 ◽  
Vol 174 ◽  
pp. 601-613
Keyword(s):  
Specific Heat ◽  
Volatile Compound ◽  
Atomic Weight ◽  
Normal Number ◽  
Vapour Density ◽  
Atomic Heat ◽  
Lothar Meyer ◽  
Free Metal

I. Introductory. Ever since the discovery of glucinum by Vauquelin, in 1798, its atomic weight has been a disputed matter amongst chemists. Its discoverer considered that its oxide was a monoide, an opinion which was however strongly opposed by Berzelius, who wrote the oxide Gl 2 O 3 and the atomic weight 13⋅7 (O=16). The researches of Awdejew and Debrayt again turned the scale in favour of the earlier view, and as an atomic weight of 9⋅2 suited the properties of the metal in the tables of periodicy constructed by MM. Mendeleef and Lothar Meyer, this atomic weight has, up to quite recently, been generally accepted by chemists. As a welcome confirmation to this came a determination of the specific heat of the metal by Professor E. Reynolds, J who found that for its atomic heat to be near the normal number 6⋅0, its atomic weight must be 9⋅2 and not 13⋅8. Almost immediately afterwards a second determination of the specific heat was made by MM. Nilson and Petterson, who, however, obtained a result agreeing not with the lower atomic weight hut with the higher. The reasons for these conflicting opinions are to be found—first, in the anomalous position of glucinum among the elements; secondly, in the difficulties which surround the preparation of even small quantities of the free metal in a tolerably pure condition; and thirdly, in the fact that no volatile compound of glucinum is known of which the vapour density might be easily determined.

Liquid-liquid equilibrium in the water-ethanol-toluene system. Experimental results

1989 ◽  
Vol 54 (3) ◽  
pp. 581-585 ◽  
Author(s):  
Květuše Říčná ◽  
Jaroslav Matouš ◽  
Josef P. Novák ◽  
Vladimír Kubíček
Keyword(s):  
Distribution Coefficient ◽  
Boiling Point ◽  
Normal Pressure ◽  
Experimental Results ◽  
Azeotropic Mixture ◽  
Liquid Equilibrium

Liquid-liquid equilibrium at 5, 25, and 50 °C was measured in the water-ethanol-toluene system. Special attention was paid to the determination of distribution coefficient of ethanol. Besides, the composition and boiling point of azeotropic mixture at normal pressure were determined.

scholarly journals XIX.—On a Mode of Taking the Density of Vapour of Volatile Liquids, at Temperatures below the Boiling Point

1861 ◽  
Vol 22 (3) ◽  
pp. 441-465 ◽  
Author(s):  
Lyon Playfair ◽  
J. A. Wanklyn
Keyword(s):  
Boiling Point ◽  
Vapour Density ◽  
Volatile Liquids ◽  
Great Discovery

The interest awakened by Gay-Lussac's great discovery of the simplicity in the relation of the volumes of gases has greatly increased in recent times, when chemists have discovered that, in a large number of instances at least, the formula of a body, as deduced physically from its vapour density, exactly coincides with that deducible from chemical considerations of its reactions, and from the nature of the products arising in consequence of them.The processes at present used for determining the vapour densities of bodies, are those of Gay-Lussac and Dumas.

scholarly journals Determination of 50% endpoint titer using a simple formula

2016 ◽  
Vol 5 (2) ◽  
pp. 85 ◽  
Author(s):  
Muthannan Andavar Ramakrishnan
Keyword(s):  
Simple Formula ◽  
Endpoint Titer
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