Word Finder - vapour

definition

Cloudy diffused matter such as mist, steam or fumes suspended in the air.

definition

The gaseous state of a substance that is normally a solid or liquid.

definition

Something insubstantial, fleeting, or transitory; unreal fancy; vain imagination; idle talk; boasting.

definition

Any medicinal agent designed for administration in the form of inhaled vapour.

definition

(in the plural) Hypochondria; melancholy; the blues; hysteria, or other nervous disorder.

definition

Wind; flatulence.

definition

To become vapor; to be emitted or circulated as vapor.

definition

To turn into vapor.

example

to vapor away a heated fluid

definition

To emit vapor or fumes.

definition

To use insubstantial language; to boast or bluster.

definition

To give (someone) the vapors; to depress, to bore.

It is very volatile, the vapour being heavy and very inflammable.

The freezing points and vapour pressures of solutions of sugar are also in conformity with the theoretical numbers.

Either they are placed in a leaden cupboard into which the vapour is introduced, or they are dipped for a few seconds in a mixture of one part of chloride of sulphur and forty parts of carbon disulphide or purified light petroleum.

The platinum is maintained at a bright red heat, either by a gas flame or by an electric furnace, and the vapour is passed over it by leading in a current of oxygen.

It possesses an extremely pungent smell, and its vapour is extremely irritating to the eyes.

These are knocked off, ground up with water, freed from metal-particles by elutriation, and the paste of white lead is allowed to set and dry in small conical forms. The German method differs from the Dutch inasmuch as the lead is suspended in a large chamber heated by ordinary means, and there exposed to the simultaneous action of vapour of aqueous acetic acid and of carbon dioxide.

It may be artificially prepared by leading sulphur vapour over lead, by fusing litharge with sulphur, or, as a black precipitate, by passing sulphuretted hydrogen into a solution of a lead salt.

In the oxyhydrogen flame silver boils, forming a blue vapour, while platinum volatilizes slowly, and osmium, though infusible, very readily.

Sulphur.-Amongst the better known metals, gold and aluminium are the only ones which, when heated with sulphur or in sulphur vapour remain unchanged.

A certain critical temperature is observed in a gas, above which the liquefaction is impossible; so that the gaseous state has two subdivisions into (i.)a true gas, which cannot be liquefied, because its temperature is above the critical temperature, (ii.) a vapour, where the temperature is below the critical, and which can ultimately be liquefied by further lowering of temperature or increase of pressure.

But this competition among inventors, whatever the incentive, has not been without benefit, because to-day, by means of very simple improvements in details, such as the addition of circulators and increased area of connexions, what may be taken to be the standard type of multiple-effect evaporator (that is to say, vertical vacuum pans fitted with vertical heating tubes, through which passes the liquor to be treated, and outside of which the steam or vapour circulates) evaporates nearly double the quantity of water per square foot of heating surface per hour which was evaporated by apparatus in use so recently as 1885 - and this without any increase in the steam pressure.

A diagram of a vapour compression machine is shown in fig.

The pressure in the refrigerator being reduced by the pump and maintained at such a degree as to give the required boiling-point, which is of course always lower than the temperature outside the coils, heat passes from the substance outside, through the coil surfaces, and is taken up by the entering liquid, which is converted into vapour at the temperature T i.

Heat is transferred from the compressed vapour to the cooling water and the vapour is converted into a liquid, which collects at the bottom and returns by the regulating valve into the refrigerator.

It is marked by the constant and continuous absorption of a certain quantity of oxygen and bythe exhalation of a certain volume of carbon dioxide and water vapour.

In the winter similar consequences ensue, in a negative direction, from the prolonged loss of heat by radiation in the long and clear nights - an effect which is intensified wherever the surface is covered with snow, or the air little charged with vapour.

The oxychloride, bromides, and other compounds were subsequently discovered; here we need only notice Moissan's preparation of the trifluoride and Thorpe's discovery of the pentafluoride, a compound of especial note, for it volatilizes unchanged, giving a vapour of normal density and so demonstrating the stability of a pentavalent phosphorus compound (the pentachloride and pentabromide dissociate into a molecule of the halogen element and phosphorus trichoride).

Columbium trichloride, CbC1 3, is obtained in needles or crystalline crusts, when the vapour of the pentachloride is slowly passed through a red-hot tube.

Columbium oxysulphide, CbOS 3, is obtained as a dark bronze coloured powder when the pentoxide is heated to a white heat in a current of carbon bisulphide vapour; or by gently heating the oxychloride in a current of sulphuretted hydrogen.

The vapour mixed with oxygen or air is violently explosive.

Its vapour produces violent headache, and the same effect is often caused by handling compositions containing it.

Its vapour is spontaneously inflammable when exposed to air.

The hexachloride, Si 2 C1 61 is formed when silicon chloride vapour is passed over strongly heated silicon; by the action of chlorine on the corresponding iodocompound, or by heating the iodo-compound with mercuric chloride (C. Friedel, Comptes rendus, 18 7 1, 73, P. 497).

Silicon tetraiodide, Si14, is formed by passing iodine vapour mixed with carbon dioxide over strongly-heated silicon (C. Friedel, Comptes rendus, 1868, 67, p. 98); the iodo-compound condenses in the colder portion of the apparatus and is purified by shaking with carbon bisulphide and with mercury.

Silicon sulphide, SiS 2, is formed by the direct union of silicon with sulphur; by the action of sulphuretted hydrogen on crystallized silicon at red heat (P. Sabatier, Comptes rendus, 1880, 90, p. 819); or by passing the vapour of carbon bisulphide over a heated mixture of silica and carbon.

Silver vapour is blue, potassium vapour is green, many others (mercury vapour, for instance) are colourless.

The metals of the alkalis and alkaline earths, also magnesium, burn in sulphur vapour as they do in oxygen.

Passed through a red-hot tube, benzene vapour yields hydrogen, diphenyl, diphenylbenzenes and acetylene; the formation of the last compound is an instance of a reversible reaction, since Berthelot found that acetylene passed through a red-hot tube gave some benzene.

Evaporation of the Juice to Syrup. - The third operation is the concentration of the approximately pure, but thin and watery, juice to syrup point, by driving off a portion of the water in vapour through some system of heating and evaporation.

A fan blast enters the lower end, and, passing out at the upper end, carries off the vapour produced by the drying of the sugar, and at the same time assists the evaporation.

After a time the flame becomes dazzling white, showing that zinc vapour is beginning to escape.

Its vapour is inflammable.

The ore, even if it is not blende, must be roasted or calcined in order to remove all volatile components as completely as possible, because these, if allowed to remain, would carry away a large proportion of the zinc vapour during the distillation.

The zinc vapour produced descends through the pipe and condenses into liquid zinc, which is collected in a ladle held under the outlet end of the pipe.

When hydraulic pressure to the amount of 2000 to 3000 lb per square inch is applied, the saving is unquestioned, since less time is required to dry the pressed retort, its life in the furnaces is longer, its absorption of zinc is less, and the loss of zinc by passage through its walls in the form of vapour is reduced.

Zinc oxide, ZnO, is maufactured for paint by two processes - directly from the ore mixed with coal by volatilization on a grate, as in the Wetherill oxide process, and by oxidizing the vapour given off by a boiling bath of zinc metal.

The temperature of the electric furnace, whether of the arc or incandescence type, is practically limited to that at which the least easily vaporized material available for electrodes is converted into vapour.

Moissan showed that at this temperature the most stable of mineral combinations are dissociated, and the most refractory elements are converted into vapour, only certain borides, silicides and metallic carbides having been found to resist the action of the heat.

By passing chloroform vapour over the heated dioxide the tetradiand tri-chlorides are formed, together with the free metal and a gaseous hydride, TiH 4 (Renz, Ber., 1906, 39, p. 2 49).

By this time it is heavily laden with vapour, which it continues to bear along across the continent, depositing it and supplying the sources of the Amazon and La Plata.

The vaporization of a substance below its normal boiling-point can also be effected by blowing in steam or some other vapour; this operation is termed "distillation with steam."

Of other common types of condenser, we may notice the "spiral" or "worm" type, which consists of a glass, copper or tin worm enclosed in a vessel in which water circulates; and the ball condenser, which consists of two concentric spheres, the vapour passing through the inner sphere and water circulating in the space between this and the outer (in another form the vapour circulates in a shell, on the outside and inside of which water circulates).

When the components are completely immiscible, the vapour pressure of the one is not influenced by the presence of the other.

The composition of the distillate is determinate (by Avogadro's law) if the molecular weights and vapour pressure of the components at the temperature of distillation be known.

If M 1, M2, and P 1, P 2 be the molecular weights and vapour pressures of the components A and B, then the ratio of A to B in the distillate is M 1 P 1 /M 2 P 2.

In general, when the substance to be distilled has a vapour pressure of only 10 mm.

A dissolved in B and B dissolved in A, since both of these solutions emit vapours of the same composition (this follows since the same vapour must be in equilibrium with both solutions, for if it were not so a cyclic system contradicting the second law of thermodynamics would be realizable).

The composition of the vapour, however, would not be the same as that of either layer.

On distilling such a mixture under constant pressure, a mixture of the two components (of variable composition) will come over until there remains in the distilling flask the mixture of minimum vapour pressure.

The vapour pressure-composition curve will now be concave to the axis of composition, the minima corresponding to the pure components.