Word Finder - reactions

definition

An action or statement in response to a stimulus or other event.

example

The announcement of the verdict brought a violent reaction.

definition

A transformation in which one or more substances is converted into another by combination or decomposition.

example

In this reaction, the acid and base will neutralize each other, producing a salt.

definition

Reactionary politics; a period in which reactionary thought or politics is resurgent or dominant.

While everyone heard the same noise, their reactions differed.

They're being influenced by your reactions.

Later, another group will test the results and record the reactions.

The aromatic aldehydes resemble the aliphatic aldehydes in most respects, but in certain reactions they exhibit an entirely different behaviour.

Repair Of Injuries In the process of inflammation we have a series of reactions on the part of the tissues, and fluids of the body, to counteract the ill effects of irritation or injury, to get rid of the cause, and to repair its results.

The dominant forms result from crustal movements, the subsidiary from secondary reactions o during the action of the primitive forms on mobile distri butions.

By his insistence upon the use of the balance as a quantitative check upon the masses involved in all chemical reactions, Lavoisier was enabled to establish by his own investigations and the results achieved by others the principle now known as the " conservation of mass."

We may here notice the important chemical symbolism or notation introduced by Berzelius, which greatly contributed to the definite and convenient representation of chemical composition and the tracing of chemical reactions.

Gerhardt attempted a solution by investigating chemical reactions.

This link was the full extension of Avogadro's theory to all substances, Cannizzaro showing that chemical reactions in themselves would not suffice.

The combination, as it is ordinarily termed, of chlorine with hydrogen, and the displacement of iodine in potassium iodide by the action of chlorine, may be cited as examples; if these reactions are represented, as such reactions very commonly are, by equations which merely express the relative weights of the bodies which enter into reaction, and of the products, thus Cl = HC1 Hydrogen.

Balard discovered chlorine monoxide in 1834, investigating its properties and reactions; and his observations on hypochlorous acid and hypochlorites led him to conclude that " bleaching-powder " or " chloride of lime " was a compound or mixture in equimolecular proportions of calcium chloride and hypochlorite, with a little calcium hydrate.

Similarly he represented the reactions investigated by Liebig and Wehler on benzoyl compounds as double decompositions.

It is necessary, therefore, to avoid reactions involving such intermolecular migrations when determining the orientation of aromatic compounds.

Hitherto we have generally restricted ourselves to syntheses which result in the production of a true benzene ring; but there are many reactions by which reduced benzene rings are synthesized, and from the compounds so obtained true benzenoid compounds may be prepared.

It must be mentioned here that the reactions of any particular substance are given under its own heading, and in this article we shall only collate the various operations and outline the general procedure.

Some of these insoluble compounds can be detected by their colour and particular reactions.

It is unnecessary here to dwell on the precautions which can only be conveniently acquired by experience; a sound appreciation of analytical methods is only possible after the reactions and characters of individual substances have been studied, and we therefore refer the reader to the articles on the particular elements and compounds for more information on this subject.

The reactions are represented as (I) N2+3H2+2C0 -1-2H 2 0=2H CO 2 NH 4 (Ammonium formate).

They give the biuret and xanthoproteic reactions, and form salts with both acids and bases.

They are loose, white, non-hygroscopic powders, soluble in water and salt solutions, and have an acid reaction; they give the colour reactions of albumins.

The mucins and mucoids belong to this group; they are acid and contain no phosphorus; they give the albumin colour reactions but are not coagulated by heat.

It is an albumin, and not a carbohydrate as was formerly held; and gives most of the colour reactions of albumins.

Moreover, a study of the chemical relations of electrolytes indicates that it is always the electrolytic ions that are concerned in their reactions.

Thus neither a chlorate, which contains the ion C103, nor monochloracetic acid, shows the reactions of chlorine, though it is, of course, present in both substances; again, the sulphates do not answer to the usual tests which indicate the presence of sulphur as sulphide.

Secondary reactions take place at the same time, yielding more particularly hydrocarbons of the paraffin series.

But his best known contribution to general chemistry is his work on the phenomena of reversible reactions, which he comprehended under a general theory of " dissociation.

Usually the cytoplasm shows a marked affinity for the acid stains, but the different bodies found in the cell may show great variation in their staining reactions.

The fat in this condition is readily recognized by the usual microchemical and staining reactions.

The reaction with iodine is seen best by direct light; the reactions with the other substances are visible only by transmitted light.

Oddi does not regard it as the essential constituent of amyloid, chiefly because the colour reactions are forthcoming in the residuum after the substance has been removed, while the substance itself does not give these reactions.

Thus Krawkow and Nowak, employing the frequent subcutaneous injection of the usual organisms of suppuration, have induced in the fowl the deposition within the tissues of a homogeneous substance giving the colour reactions of true amyloid.

When hardened in spirit, however, the greater part of this experimental amyloid in the fowl vanishes, and the reactions are not forthcoming.

These are peculiar bodies which are found in the prostate, in the central nervous system, in the lung, and in other localities, and which get their name from being very like starch-corpuscles, and from giving certain colour reactions closely resembling those of vegetable cellulose or even starch itself.

It further resembles true amyloid in giving all its colour reactions.

Now, what is remarkable in these and many other reactions is not only that effects apparently very opposite may result from minute differences of molecular construction, but also that, whatever the construction, agents, not wholly indifferent to the body or part, tend to anchor themselves to organic molecules in some way akin to them.

It is convenient here to add that such reactions and modifications, if more conspicuous in the nervous system, are of course not confined to it, but are concerned in their degree in all the processes of metabolism, being most readily traced by us in the blood.

They show all the reactions of esters, being readily hydrolysed by caustic alkalis, and reacting with ammonia to produce carhamic esters and urea.

Of the heavy metals, copper is the one which exhibits by far the greatest avidity for sulphur, its subsulphide Cu 2 S being the stablest of all heavy metallic sulphides in opposition to dry reactions.

These reactions permit the transformation of an aldose into a ketose; the reverse change can only be brought about by reducing the ketose to an alcohol, and oxidizing this compound to an aldehyde.

The present article, as explained under Electrochemistry, treats only of those processes in which electricity is applied to the production of chemical reactions or molecular changes at furnace temperatures.

The furnace used by Henri Moissan in his experiments on reactions at high temperatures, on the fusion and volatilization of refractory materials, and on the formation of carbides, suicides and borides of various metals, consisted, in its simplest form, of two superposed blocks of lime or of limestone with a central cavity cut in the lower block, and with a corresponding but much shallower inverted cavity in the upper block, which thus formed the lid of the furnace.

In these processes the electric current is used solely to generate heat, either to induce chemical reactions between admixed substances, or to produce a physical (allotropic) modification of a given substance.

If, however, no porous division be used to prevent the intermingling by diffusion of the anode and cathode solutions, a complicated set of subsidiary reactions takes place.

Again, anode reactions, such as are observed in the electrolysis of the fatty acids, may be utilized, as, for example, when the radical CH3C02 - deposited at the anode in the electrolysis of acetic acid - is dissociated, two of the groups react to give one molecule of ethane, C 2 H 6, and two of carbon dioxide.

There are certain reactions, however, in which oxidation can be successfully applied to the synthesis of acids.

Of foremost importance are the reactions termed the malonic acid and the aceto-acetic ester syntheses; these are discussed under their own headings.

Torbern Olof Bergman reinvestigated its properties and determined its reactions; his account, which was published in his Opuscula, contains the first fairly accurate description of the metal.

When A is held still, and B rotated, centrifugal action sets up vortex currents in the water in the pockets; thus a continuous circulation is caused between B and A, and the consequent changes of momentum give rise to oblique reactions.

The moments of the components of these actions and reactions in a plane to which the axis of rotation is at right angles are the two aspects of the torque acting, and therefore the torque acting on B through the shaft is measured by the torque required to hold A still.