The cobaltous salts are formed when the metal, cobaltous oxide, hydroxide or carbonate, are dissolved in acids, or, in the case of the insoluble salts, by precipitation.
The neutralization of acids by bases affords many illustrations, known even before the atomic theory, of the truth of the statement.
It decomposes steam at a red heat, and slowly dissolves in dilute hydrochloric and sulphuric acids, but more readily in nitric acid.
It is readily soluble in warm dilute mineral acids forming cobaltous salts.
This hydroxide is soluble in well cooled acids, forming solutions which contain cobaltic salts, one of the most stable of which is the acetate.
They are precipitated from their alkaline solutions as cobalt sulphide by sulphuretted hydrogen, but this precipitation is prevented by the presence of citric and tartaric acids; similarly the presence of ammonium salts hinders their precipitation by caustic alkalis.
It is a black amorphous powder soluble in concentrated sulphuric and hydrochloric acids, and when in the moist state readily oxidizes on exposure.
It is insoluble in dilute acids, but is readily soluble in excess of potassium cyanide.
They are violet-red in colour, and on boiling or long standing with dilute acids they pass into the corresponding roseo-salts.
The pentammine roseo-salts can be obtained from the action of concentrated acids, in the cold, on airoxidized solutions of cobaltous salts.
They are of a reddish colour and usually crystallize well; on heating with concentrated acids are usually transformed into the purpureo-salts.
It is somewhat readily oxidized; nitric acid gives carbonic and oxalic acids, and chromic acid, carbonic and acetic acids.
They are easily hydrolysed, breaking up into their components when boiled with acids or alkalies.
The secondary and tertiary amides of the types (RCO) 2 NH and (RCO) 3 N may be prepared by heating the primary amides or the nitriles with acids or acid anhydrides to 200° C. Thiamides of the type R.
The free acid, which is obtained by treating the salts with acids, is an oily liquid smelling like prussic acid; it is very explosive, and the vapour is poisonous to about the same degree as that of prussic acid.
On oxidation with chromic or nitric acids, or potassium permanganate, it yields nicotinic acid or (3-pyridine carboxylic acid, C 5 H 4 N CO 2 H; alkaline potassium ferricyanide gives nicotyrine, C10H10N2, and hydrogen peroxide oxynicotine, C10H14N20.
The metal is quite permanent in dry air, but in moist air it becomes coated with a superficial layer of the oxide; it burns on heating to redness, forming a brown coloured oxide; and is readily soluble in mineral acids with formation of the corresponding salts.
It is a basic oxide, dissolving readily in acids, with the formation of salts, somewhat analogous to those of zinc.
This precipitate is insoluble in cold dilute acids, in ammonium sulphide, and in solutions of the caustic alkalis," a behaviour which distinguishes it from the yellow sulphides of arsenic and tin.
Molybdenum sesquioxide, Mo 2 O 3, a black mass insoluble in acids, is formed by heating the corresponding hydroxide in vacuo, or by digesting the trioxide with zinc and hydrochloric acid.
The molybdates may be recognized by the fact that they give a white precipitate on the addition of hydrochloric or nitric acids to their solutions, and that with reducing agents (zinc and sulphuric acid) they give generally a blue coloration which turns to a green and finally to a brown colour.
Chlorophyll is not soluble in water, nor in acids or alkalies without decomposition.
The fate of these inorganiccompounds has not been certainly traced, but they give rise later on to the presence in the plant of various amino acid amides, such as leucin, glycin, asparagin, &c. That these are stages on the way to proteids has been inferred from the fact that when proteids are split up by various means, and especially by the digestive secretions, these nitrogen-containing acids are among the products which result.
The other group attacks these peptones and breaks them down into the amino-acids of which we have spoken before.
The inability to enter the cells may be due to the lack of chemotactic bodies, to incapacity to form cellulose-dissolving enzymes, to the existence in the hostcells of antagonistic bodies which neutralize or destroy the acids, enzymes or poisons formed by the hyphae, or even to the formation and excretion of bodies which poison the Fungus.
The cell sap contains various substances in solution such as sugars, inulin, alkaloids, glucosides, organic acids and various inorganic salts.
The oxides of type RO are soluble in water, the solution possessing a strongly alkaline reaction and rapidly absorbing carbon dioxide on exposure; they are basic in character and dissolve readily in acids with the formation of the corresponding salts.
Phenol dissolves readily in concentrated sulphuric acid, a mixture of phenol-orthoand -para-sulphonic acids being formed.
Carbolic acid is distinguished from all other acids so-called - except oxalic acid and hydrocyanic acid - in that it is a neurotic poison, having a marked action directly upon the nervous system.
In many cases it acts as a reducing agent (when used in the presence of acids); thus, permanganates are reduced to manganous salts, iodates are reduced with liberation of iodine, &c., 2KMnO 4 + 550 2 + 2H 2 0 = K 2 SO 4 + 2MnSO 4 + 2H 2 SO 4; 2K103+ 550 2 + 4H 2 O =1 3 + 2KHSO 4 + 3H2S04.
It is readily decomposed by water with formation of sulphurous, sulphuric and thiosulphuric acids, with simultaneous liberation of sulphur.
The thiosulphates are readily decomposed by mineral acids with liberation of sulphur dioxide and precipitation of sulphur: Na 2 S 2 0 3 + 2HC1 = 2NaC1 + S + SO 2 + H 2 O.
The thionic acids are a group of sulphur-containing acids of general formula H2S006, where n=2, 3, 4, possibly 6.
Chim., 1906, 2 5, p. 2 53) considers to be a hydrate of sulphur of composition S $ H 2 0), sulphuric acid, traces of trithionic acid, tetraand pentathionic acids and probably hexathionic acid.
The per-acids of sulphur were first obtained in 1898 by Caro (Zeit.
Both of these statements are correct when the powerful mineral acid and bases are considered, exceptions only arising when weak acids and bases are employed.
Silbermann, whose chief theoretical achievement was the recognition that the heat of neutralization of acids and bases was additively composed of two constants, one determined by the acid and the other by the base.
It has already been stated that the heats of neutralization of acids and bases in aqueous solution are additively composed of two terms, one being constant for a given base, the other constant for a given acid.
In addition to this, the further regularity has been observed that when the powerful monobasic acids are neutralized by the powerful monacid bases, the heat of neutralization is in all cases the same.
The following table gives the heats of neutralization of the commoner strong monobasic acids with soda: - Hydrochloric acid Hydrobromic acid Hydriodic acid Nitric acid Chloric acid Bromic acid Within the error of experiment these numbers are identical.
To him belongs the merit of carrying out some of the earliest determinations of the quantities by weight in which acids saturate bases and bases acids, and of arriving at the conception that those amounts of different bases which can saturate the same quantity of a particular acid are equivalent to each other.
He was thus led to conclude that chemistry is a branch of applied mathematics and to endeavour to trace a law according to which the quantities of different bases required to saturate a given acid formed an arithmetical, and the quantities of acids saturating a given base a geometrical, progression.
Berthelot, and many other chemists, from whose researches it results that glycerin is a trihydric alcohol indicated by the formula C 3 H 5 (OH) 3j the natural fats and oils, and the glycerides generally, being substances of the nature of compound esters formed from glycerin by the replacement of the hydrogen of the OH groups by the radicals of certain acids, called for that reason "fatty acids."
It was that of two tartaric acids, deposited from wine-lees.
The different behaviour of these two acids to a ray of polarized light was subsequently observed by J.
These esters are readily hydrolysed and yield the monoand di-alkylimalonic acids which, on heating, are readily decomposed, with evolution of carbon dioxide and the formation of monoand di-alkyl acetic acids.
Another mode of separating the two acids is to convert them into calcium salts, which are then treated with a perfectly neutral solution of cupric chloride, soluble cupric citrate and calcium chloride being formed, while cupric tartrate remains undissolved.
The rationale of this treatment is not fully understood, but the action appears to consist in the separation or decomposition of the aromatic hydrocarbons, fatty and other acids, phenols, tarry bodies, &c., which lower the quality of the oil, the sulphuric acid removing some, while the caustic soda takes out the remainder, and neutralizes the acid which has been left in the oil.
In a scientific definition the compounds of fatty acids with basic metallic oxides, lime, magnesia, lead oxide, &c., should also be included under soap; but, as these compounds are insoluble in water, while the very essence of a soap in its industrial relations is solubility, it is better to speak of the insoluble compounds as " plasters, " limiting the name " soap " as the compounds of fatty acids with soda and potash.
It dissolves in acids forming cobaltous salts, and on exposure to air it rapidly absorbs oxygen, turning brown in colour.
Its methyl derivatives yield the corresponding carboxylic acids when oxidized by potassium permanganate.
Berzelius by the dry distillation of tartaric or racemic acids (Pogg.
FULMINIC ACID, Hcno or H 2 C 2 N 2 0 2, an organic acid isomeric with cyanic and cyanuric acids; its salts, termed fulminates, are very explosive and are much employed as detonators.