scholarly journals II. Note on the decomposition of sulphuric acid by pentachloride of phosphorus

1856 ◽  
Vol 7 ◽  
pp. 11-15 ◽  
Keyword(s):  
Nitric Acid ◽  
Sulphuric Acid ◽  
Mechanical Mixture ◽  
The Other ◽  
Acid Sulphate ◽  
Other Hand ◽  
Equivalent Quantity

Chemists have long been aware of the fact that some acids unite with bases in one proportion only, others in two or more proportions. Thus a given quantity of nitric acid forms with what is termed its equivalent of potash, a definite nitrate of potash; if less than this equivalent quantity of potash were added to the nitric acid, the product would be a mechanical mixture of the same nitrate of potash with uncombined nitric acid; if more than the equivalent of potash were added, the excess of alkali would remain uncombined. Sulphuric acid, on the other hand, is capable of forming two compounds with potash, and it depends upon the proportions in which the two substances are brought together whether the neutral or acid sulphate is formed.

III.—On the Reduction of Ferric Iron (1) by Sulphurous Acid and (2) by Zinc Dust

1913 ◽  
Vol 32 ◽  
pp. 12-16
Author(s):  
Alexander Charles Cumming ◽  
E. W. Hamilton Smith
Keyword(s):  
Sulphuric Acid ◽  
Carbonate Rocks ◽  
Ferric Iron ◽  
Zinc Dust ◽  
The Other ◽  
Additional Contribution ◽  
Large Excess ◽  
Other Hand

So many papers have appeared on this subject that some apology seems desirable before making an additional contribution. The amount of published work on reduction with sulphurous acid is in itself an indication that many workers have found difficulties. It has been shown that the reduction does not take place in presence of large excess of hydrochloric or sulphuric acid, but the reduction will still occur while the reaction of the solution is strongly acid. On the other hand, Hillebrand (“Analysis of Silicate and Carbonate Rocks,” U.S. Bulletin, 442, p. 113) states if the solution after addition of sulphite is red in colour, it is too alkaline and acid must be added.

Photochemistry of 2,2'-dinitrodiphenylmethanes: Irradiations in neutral, acidic and alkaline media

1976 ◽  
Vol 29 (4) ◽  
pp. 865 ◽  
Author(s):  
CP Joshua ◽  
PK Ramdas
Keyword(s):  
Sulphuric Acid ◽  
Isopropyl Alcohol ◽  
Major Product ◽  
The Other ◽  
Alkaline Media ◽  
Other Hand ◽  
Acidic And Alkaline Media

Photolysis of 2,2'-dinitrodiphenylmethane (1) in isopropyl alcohol affords dibenzo[c,f][l,2]diazepin-11-one 5-oxide (7) as the major product. Dibenzo[c,f][l,2]diazepin-11-one 5,6-dioxide (6), acridone (8) and 2,2'-dinitrobenzophenone (9) are also formed in the reaction. Irradiation of (1) in ethanolic sulphuric acid on the other hand yields 3-(2'-nitropheny1)-2,l-benzisoxazole (11) as the major product; small amounts of (7), (8) and (9) are also isolated. Photoconversion of (1) in triethylamine and alcoholic triethylamine proceeds very slowly and compounds (7), (8) and (9) only are isolated from the photolysed solution. Some aspects of the mechanism are discussed.

COMPARISON OF THE NITROLYSIS OF 1, 3-DICYCLOHEXYLIMIDAZOLIDINE WITH THAT OF HEXAMETHYLENETETRAMINE

1950 ◽  
Vol 28b (5) ◽  
pp. 213-224 ◽  
Author(s):  
J. L. Boivin ◽  
George F Wright
Keyword(s):  
Nitric Acid ◽  
Ammonium Nitrate ◽  
The Other ◽  
Nitrate Salt ◽  
Other Hand ◽  
Dinitro Derivative ◽  
Basic Amine

The nitrolysis of N,N′-dicyclohexylimidazolidine has been effected with formation of the nitrate salt, the nitroso derivative, and the aceto derivative of N,N′-dicyclohexyl-N-nitro-1,2-diaminoethane. The absence of the dinitro derivative suggests that demethylolation is not related to nitramine formation. When formaldehyde splits off to leave a weakly basic amine, as in hexamethylenetetramine nitrolysis, then subsequent nitration will occur; but it will not take place if the resulting amine is strongly basic. Nitrolysis will depend also on reactivity of nitric acid, which can be decreased by addition of ammonium nitrate. This decrease will prevent esterification of intermediate N-methylolamines but not nitrolysis of hexamethylenetetramine types. However both nitrolysis and esterification are thus prevented with dicyclohexylimidazolidine. On the other hand the two nitrolyses are related by the fact that both are accelerated by electropositive chlorine.

scholarly journals Chemical action that is stimulated by alternating currents

1914 ◽  
Vol 90 (615) ◽  
pp. 26-32
Keyword(s):  
Sulphuric Acid ◽  
Alternating Current ◽  
The Other ◽  
Chemical Action ◽  
Local Circuit ◽  
Low Resistance ◽  
Other Hand ◽  
Continuous Current ◽  
Voltaic Cell

The following experiments were carried out in the year 1905. Taking a simple voltaic cell, consisting of an anode and cathode of zinc and carbon, and an electrolyte of dilute sulphuric acid, it was found that polarisation, which takes place when the cell is joined to a local circuit of low resistance, could be diminished or completely abolished, by passing through the cell an alternating current of suitable value. Fig. 1 illustrates the arrangement of the cell, D, joined up to deliver current through the ampèremeter, B; under these conditions the cell is very quickly polarised, and the continuous current falls to a very low figure. On the other hand, if a suitable strength of alternating current of. say, 100 periods per second is sent through the cell from the leads A, the cell D will be completely depolarised and will give its full current delivery. L is a self-induction and K a capacity to prevent the alternating and continuous currents from flowing in each other's circuit, the only part of the circuit common to both being through the cell.

scholarly journals Results of the interaction of mercury with alloys of other metals

1908 ◽  
Vol 80 (536) ◽  
pp. 83-87 ◽  
Keyword(s):  
Nitric Acid ◽  
Sulphuric Acid ◽  
The Other ◽  
Metallic Mercury ◽  
Great Resistance ◽  
Aqua Regia ◽  
The One

It is well known that alloying metals with each other often modifies in a remarkable way their several relations to acids and other non-metallic reagents. Examples of this are afforded by the addition of silver to platinum, rendering the latter soluble, along with the former, in nitric acid —by the great resistance to the action of aqua regia on platinum when alloyed with rhodium or iridium—and by the solubility in cold, somewhat dilute sulphuric acid, of copper in alloy with nickel and zinc as common “German silver.” It seemed interesting to see what the behaviour of fluid metallic mercury would be in relation to alloys of metals solid at common temperatures. For instance, if an alloy of two metals—one of them when alone amalgamating readily with mercury and the other not—should be exposed to the action of mercury, would the former resist amalgamation or the latter be rendered amalgamable, or would each continue to behave as though the other were absent and the mercury take up the one and leave the other intact?

THE ACETOLYSES OF THE ALPHA AND BETA METHYL D-GLUCOPYRANOSIDE TETRAACETATES

1955 ◽  
Vol 33 (1) ◽  
pp. 148-162 ◽  
Author(s):  
R. U. Lemieux ◽  
W. P. Shyluk ◽  
G. Huber
Keyword(s):  
Acetic Acid ◽  
Acetic Anhydride ◽  
Sulphuric Acid ◽  
Reaction Mechanisms ◽  
The Other ◽  
Isotopic Dilution ◽  
Other Hand ◽  
Anomeric Center ◽  
Reaction Routes ◽  
Isotopic Dilution Analysis

The acetolyses of the alpha and beta methyl D-glucopyranoside tetraacetates in 1:1 acetic acid – acetic anhydride 0.5 M with respect to sulphuric acid were followed at 25 °C. by isotopic dilution analysis of products isolated after various intervals of time. The reaction of the α-glucoside was found to proceed mainly with inversion of the anomeric center. On the other hand, the β-glucoside was found to undergo acetolysis with retention of configuration concurrent with anomerization. It was shown that the polarimetric changes observed in the course of the reactions could be satisfactorily accounted for on the basis of these reaction routes. Reaction mechanisms are suggested.

On the cause of the reduction of metals from solutions of their salts by the voltaic circuit

1843 ◽  
Vol 4 ◽  
pp. 447-448
Keyword(s):  
Nitric Acid ◽  
Acid Solution ◽  
Large Scale ◽  
Saline Solution ◽  
The Other ◽  
Negative Pole ◽  
Other Hand ◽  
Metallic Salt ◽  
Electric Polarity

The reduction of a metal from its saline solution by the agency of voltaic electricity, has, the author states, been explained in three different ways. By Hisinger, by Berzelius, and by Faraday it has been ascribed to the liberation of hydrogen in this process: Davy and others considered it as resulting directly from the attraction o the metal to the negative pole: and Daniell conceives that the metal is directly electrolysed by the action of the voltaic circuit. The author found that the ends of copper wires, placed in a solution of sulphate of copper between two platina poles in the circuit, mani­fest electric polarity; so that while one end is dissolving, the other is receiving deposits of copper: he also found that platina was, in like manner, susceptible of polarity, although in a much less degree than copper, when placed in similar circumstances. With a view to determine the influence of nascent hydrogen in the voltaic reduc­tion of metals, he impregnated pieces of coke and of porous char­coal with hydrogen, by placing them, while in contact with a metal, in an acid solution, when they thus constituted the negative pole of the circuit; and he found that the pieces thus charged readily re­duced the metals of solutions into which they were immersed; and thence infers that the hydrogen is the agent in these reductions. From another set of experiments he concludes, that during these decompositions, water is really formed at the negative pole; a circumstance which he conceives is the chief source of the difficulties ex­perienced in electro-metallurgic operations when they are conducted on a large scale, but which may be avoided by a particular mode of arranging the elements of the circuit so as to ensure the uniform diffusion of the salt. The author obtained the immediate reduction of gold, platina, palladium, copper, silver and tin from their solutions by the agency of hydrogen contained in a tube, with a piece of platinized platina in contact with the metallic salt: nitric acid and persalts of iron, on the other hand, yielded their oxygen by the influence of the same agent.

A Tritium–Hydrogen Exchange Procedure for Determining the Concentration of Exchangeable Sites on PAN Based Carbon Fibres

1997 ◽  
Vol 9 (3) ◽  
pp. 281-290 ◽  
Author(s):  
Ian Hamerton ◽  
John N Hay ◽  
Brendan J Howlin ◽  
John R Jones ◽  
Shui-Yu Lu ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Active Sites ◽  
Hydrogen Exchange ◽  
The Other ◽  
Carbon Fibres ◽  
Other Hand ◽  
Non Destructive

A non-destructive tritium–hydrogen exchange procedure has been developed in order to determine the concentration of exchangeable hydrogens on surfaces, and in this particular instance it has been used on carbon fibres. The results show that the concentrations of ‘active sites’ on the surfaces of Courtaulds Grafil XAS and XAU carbon fibres are 2.61 and 0.08 μmol g−1 respectively. When the XAS fibres are subjected to a standard methylation procedure the concentration of exchangeable hydrogens is reduced to 0.79 μmol g−1.On the other hand, when XAU fibres are subjected to oxidation in concentrated nitric acid, the concentration of exchangeable hydrogens is increased to 10.27 μmol g−1.

scholarly journals 3. On the Products of the Oxidation of Dimethyl-Thetine, and its Derivatives

1875 ◽  
Vol 8 ◽  
pp. 508-509
Author(s):  
Crum Brown ◽  
E. A. Letts
Keyword(s):  
Nitric Acid ◽  
Sulphuric Acid ◽  
The Other ◽  
Soluble Salt ◽  
Acid Properties ◽  
Basic Properties ◽  
The One ◽  
Two Bodies ◽  
Dilute Nitric Acid

The difficulty experienced in determining the sulphur contained in the compounds of dimethyl-thetine (described in a former communication) by oxidation to sulphuric acid, induced the authors to study the effects of various oxidising agents on these compounds.By acting on nitrate of dimethyl-thetine with dilute nitric acid, two bodies are produced. The one has acid properties, and forms a well-marked soluble salt with baryta. The other has neither acid nor basic properties. It crystallises in very beautiful needles from a hot solution in alcohol.

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