Nitrogen gas

“ Blow a candle out; and while the wick is still red, hold the candle (by a piece of wire,) in the bottle of oxygen gas; the wick will instantly ignite, and burn brilliantly.
(Burning sulphur emits a blue flame, when immersed in oxygen gas.)
Q. What is nitrogen?
A. Nitrogen is another invisible gas. It will not burn, like hydrogen; and [Pg 36] an animal cannot live in it: it abounds in animal and vegetable substances, and is the chief ingredient of the common air. [9]
[9] Nitrogen gas may easily be obtained thus:—Put a piece of burning phosphorus on a little stand, in a plate of water ”

“ When burning coal, however, the percentage of nitrogen is obtained by subtracting the sum of the percentages by volume of the other gases from 100. Thus if an analysis shows 12.5 per cent CO 2 , 6.5 per cent O, and 0.6 per cent CO, the percentage of nitrogen which ordinarily is the only other constituent of the gas which need be considered, is found as follows:
The action of the hydrogen in the volatile constituents of the fuel is to increase the apparent percentage of the nitrogen in the flue gases. ”

“ In all these processes the action of the gas is impeded by the bulky presence of its fellow constituent of air, nitrogen. We may say, for instance, in homely phrase, that whenever a fire burns there are four volumes of nitrogen tending to extinguish it for every volume of oxygen supporting its combustion, and to the same degree the nitrogen interferes with all other processes of atmospheric oxidation, of which most metallurgical operations may be given as instances. ”

“ The fact that the oxygen of the air is diluted as it were with so large a proportion of nitrogen, prevents fires from sweeping over the world and destroying everything in their path. Nitrogen does not support combustion, and a burning match placed in a corked bottle goes out as soon as it has used up the oxygen in the bottle. The nitrogen in the bottle, not only does not assist the burning of the match, but it acts as a damper to the burning.
Free nitrogen, like oxygen, is a colorless, odorless gas. ”

“ We have already made some reference to this gas when speaking of the atmosphere and its constituents, of which nitrogen is the principal. From its life-destroying properties it is called “azote” by French chemists, and when we wish to obtain a supply of nitrogen all we have to do is to take away the oxygen from the air by burning phosphorus on water under a glass. Nitrogen is not found frequently in solid portions of the globe. It is abundant in animals. It is without colour or smell, and can be breathed in air without danger. ”

“ The two constituents of the oxygen gas being thus disposed of, what remains under the receiver must be pure nitrogen gas?
MRS. B.
There are some circumstances which prevent the nitrogen gas, thus obtained, from being perfectly pure; but we may easily try whether the 195 oxygen has disappeared, by putting another lighted taper under it.—You see how instantaneously the flame is extinguished, for want of oxygen to supply the negative electricity required for the formation of caloric; and were you to put an animal under the receiver, it would immediately be suffocated. ”

“ The nitric acid, as it becomes free, gives a part of its oxygen to the phosphorous compound, and the nitrous acid, in a nascent state, is at once reduced by the ammonium chlorid. There are two sources of error which must be guarded against in the work; a portion of the nitrogen may escape reduction to the elementary state, or some of the nitrate may fail to be decomposed. These errors are easily avoided if the reaction be begun slowly, so that the evolution of gas may be gradual. ”

“ During their determinations of the density of nitrogen they noticed that the density of nitrogen derived from the air differed from the density of nitrogen derived from ammonia and other compounds of nitrogen, and after a series of very careful experiments they succeeded in isolating a new gas, which they named Argon. The gas occurs in sea and river water, in plants, in the blood of animals, and the gases issuing from volcanoes and mineral springs. It is always in the free state and never in combination, and is associated with nitrogen. ”

“ Nitrogen, which constitutes by measure 79.04, and by weight 76.8 of the air, is remarkable for the absence of positive qualities. It is a colorless, tasteless, odorless gas, will not burn, nor support life or combustion. Its chief office is that of a diluter. Without it we should live too fast; even as it is we live too fast! With oxygen alone to breathe, ours would be a short and fevered existence. All flames and fires would be kindled into furious combustion, stoves themselves would burn, and the very “elements melt with fervent heat.”
MERCURY DISSOLVING IN NITRIC ACID. ”

“ Considerable interest has been aroused lately in scientific and industrial circles by a report that separation of the oxygen and nitrogen of the air was being effected on a large scale in London by a process which promises to render the gases available for general application in the arts. The cheap manufacture of the compounds of nitrogen from the gas itself is still a dream of chemical enthusiasts ”

“ When it became known (Chapter V., Note 4 bis) that the nitrogen obtained from air (by removing the oxygen, moisture and CO2, by various reagents) has a greater density than that obtained from the various (oxygen, hydrogen and metallic) compounds of nitrogen, it was a plausible explanation that the latter contained an admixture of hydrogen, or of some other light gas lowering the density of the mixture. ”

“ Nitrogen is mainly characterised by negative properties, although many of its compounds are very energetic bodies. It is a gas, present everywhere, but so inactive that the assayer can always afford to ignore its presence, and, except in testing furnace gases, &c., he is never called on to determine its quantity. ”

“ If only consisting of nitrogen, the human race would also die, because this element is incapable of supporting life; people would be suffocated, in fact.
Therefore, a judicious mixture of the two is essential to the life of animals. Generally, in a hundred parts of air by weight there are seventy-six parts of nitrogen to twenty-three of oxygen.
Besides these two gases, there is also a quantity of carbonic acid gas in the air, given off by all the fires and animals in the world. Of course, its amount is much greater in the great towns and manufacturing centers than in country districts. ”

“ Nitrogen is a very inert gas: it will neither burn nor support the combustion of ordinary combustibles. It combines directly with lithium, calcium and magnesium when heated, whilst nitricles of the rare earth metals are also produced when their oxides are mixed with magnesium and heated in a current of nitrogen (C. Matignon, Comptes rendus, 1900, 131, p. 837) . Nitrogen has been liquefied, the critical temperature being −149° C. and the critical pressure 27-54 atmospheres. ”

“ Nitrogen is a substance also generally diffused through nature, and particularly in animal bodies, and causes great changes in those absorbing or exposed to it. This gas, combined with oxygen and hydrogen, produces neither light, heat, nor combustion, but serves to dilute the others: of itself, it is hurtful to animal life. Nitrogen makes the principal part of the salt we call nitre. ”

“ Nitrogen, itself, is an inert gas of no particular use, but nitrogenous compounds are necessary to agriculture, to refrigeration, to munitions manufacture, and to the applications of chemistry in general. In the native gaseous state, it makes up about four-fifths of the atmosphere, and combined it occurs as nitrate minerals, as organic compounds, and in carboniferous deposits. ”

“ As the nitrogen boils at a lower temperature (-194° C. or 318° F.) than oxygen (-183° C. or 297° F.) , more nitrogen is converted into gas in a given time than oxygen, and after a time the liquid that is left is much richer in oxygen than ordinary air. When liquid air is poured upon water it, being a little lighter than the water, floats, not quietly, to be sure, but in a very troubled way. Soon, however, the liquid sinks to the bottom because the nitrogen, which is the lighter constituent, passes into the gaseous state, and the liquid oxygen which is left is a little heavier than water. ”

“ Nitrogen also occurs in nature in the form of potassium nitrate (KNO3) —commonly called saltpeter or niter—as well as in sodium nitrate (NaNO3) . Nitrogen is also an essential constituent of all living organisms; for example, the human body contains about 2.4% of nitrogen.
Preparation from air. Nitrogen can be prepared from air by the action of some substance which will combine with the oxygen, leaving the nitrogen free. Such a substance must be chosen, however, as will combine with the oxygen to form a product which is not a gas, and which can be readily separated from the nitrogen. ”

“ On the other hand, if a strong solution of nitrate of ammonia be decomposed, oxygen appears at the positive pole, and hydrogen, with sometimes nitrogen, at the negative pole. If fused nitrate of ammonia be employed, hydrogen appears at the negative pole, mingled with a little nitrogen. Strong nitric acid yields plenty of oxygen at the positive pole, but no gas (only nitrous acid) at the negative pole. Weak nitric acid yields the oxygen and hydrogen of the water present, the acid apparently remaining unchanged. ”

“ In other words, the combination of hydrogen with oxygen is an exothermal reaction, and the combination of nitrogen with oxygen an endothermal reaction.
A condition particularly favourable for the oxidation of nitrogen is the explosion of detonating gas and air if the former be in excess. If a mixture of two volumes of detonating gas and one volume of air be exploded, then one-tenth of the air is converted into nitric acid, and consequently after the explosion has taken place there remain only nine-tenths of the volume of air originally taken. ”

“ For this reason nitrous oxide formed by the condensation of two permanent gases is a substance which is somewhat easily converted into a liquid; again, nitric acid, which is formed from elements which are permanent gases, is a liquid, whilst, on the contrary, nitric oxide, which is formed without contraction and is decomposed without expansion, remains a gas which is as difficult to liquefy as nitrogen and oxygen. ”

“ By exposing nitrite of ammonia to heat in a retort, nitrogen comes over alone in great abundance; for the hydrogen of the ammonia is sufficient to saturate the oxygen of the acid, and to convert it into water; while the nitrogen of both constituents is set at liberty. By transmitting chlorine through water of ammonia, or digesting lean flesh in warm nitric acid, nitrogen may also be obtained. This permanently elastic gas is destitute of colour, taste, and smell; it has a specific gravity of 0·976, air being 1·000. ”

“ This gas, mixed with the atmosphere in which it has been generated, may now be passed through a reservoir of water, and the [309] new gas combines with a portion of water to form nitric acid, each molecule of which is a compound of one atom of hydrogen, one atom of nitrogen, and three atoms of oxygen; and nitric acid, as everyone knows, is a very active substance, as marked in its eagerness to unite with other substances as pure nitrogen is in its aloofness. ”

“ The oxygen, carbonic acid, and nitrogen, being incombustible, injure the illuminating power very greatly. The oxygen and nitrogen are admitted accidentally by the introduction of a little air in charging the retorts. Hence, other things being equal the illuminating power of the gas increases with the proportion of olefiant and other hydrocarbons, and these depend chiefly on the kind of coal used and the temperature at which it is carbonized. The gas-coals are the bituminous caking coals and cannel. ”

“ Traces of nitrous and nitric acid are also present in the air, produced by the direct combination of nitrogen and oxygen occurring as the result of the electric spark during lightning.
Carbonic Acid or carbon dioxide is always present in air, in the proportion of 3·36 to 4 parts in 10,000; but in impure air may be present in much larger amount. It is a heavy gas, incapable of supporting combustion, and therefore of supporting animal life. Being a heavy gas, it tends to accumulate where it is produced, as about lime-kilns by the heating of chalk. ”

“ The same odor is perceptible around stables and other places where animal matter is decomposing. All animal muscle, certain parts of plants, and other organized substances, consist of compounds containing nitrogen. When these compounds undergo combustion, or are in any manner decomposed, the nitrogen which they contain usually unites with hydrogen, and forms ammonia. In consequence of this the atmosphere always contains more or less of this gas, arising from the decay, etc., which is continually going on all over the world. ”

“ Mix nitrous gas and air together in a jar over water, and the nitrous gas takes away the oxygen, and then the water sucks up the mixed oxygen and nitrous gas, and that part of the air which weakens the oxygen is left behind. Burning phosphorus in confined air will also take all the oxygen from it, and there are other ways of doing the same thing. The portion of the air left behind is called nitrogen. ”

“ Carbon burned in protoxide of nitrogen, or laughing gas, N2O, produces about 38 per cent. more heat than the same substance burned in pure oxygen, notwithstanding that the work of decomposing the protoxide of nitrogen has to be performed. In marsh gas, or methane, CH4, again, the energy of combustion is considerably less than that due to the burning of its carbon and hydrogen separately. ”