Halogen sentence example
It is decomposed by the halogen elements and also by sulphuretted hydrogen.
This change only occurs when the halogen atom is in the orthoor paraposition to the - N2 - group.
Molybdenum combines with the halogen elements in varying proportions, forming with chlorine a di-, tri-, tetraand penta-chloride, and similar compounds with bromine and iodine.
Similarly, the formation of organic halogen products may be effected by electrolytic chlorine, as, for example, in the production of chloral by the gradual introduction of alcohol into an anode cell in which the electrolyte is a strong solution of potassium chloride.
It is to be noted that only traces of the aromatic amines are produced by heating the halogen substituted benzenes with ammonia, unless the amino group be situated in the side chain, as in the case of benzylamine.Advertisement
In formulating these facts Liebig at first retained the dualistic conception of the structure of acids; but he shortly afterwards perceived that this view lacked generality since the halogen acids, which contained no oxygen but yet formed salts exactly similar in properties to those containing oxygen, could not be so regarded.
The amino derivatives are stable bases which readily yield substitution derivatives when acted upon by the halogen elements.
The same absorbent' quantitatively takes up any halogen and sulphur which may be present.
Halogen acids convert it into monohalogen fatty acids, and the halogens themselves convert it into dihalogen fatty acids.
Balard completed for many years Berzelius's group of " halogen " elements; the remaining member, fluorine, notwithstanding many attempts, remained unisolated until 1886, when Henri Moissan obtained it by the electrolysis of potassium fluoride dissolved in hydrofluoric acid.Advertisement
We may, in fact, consider that the descriptive study of the various halogen compounds dates from about this time.
Of the halogen compounds of phosphorus, the trichloride was discovered by Gay Lussac and Thenard, while the pentachloride was obtained by Davy.
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).
From the fact that reduction products containing either one or two double linkages behave exactly as unsaturated aliphatic compounds, being readily reduced or oxidized, and combining with the halogen elements and haloid acids, it seems probable that in benzenoid compounds the fourth valencies are symmetrically distributed in such a manner as to induce a peculiar stability in the molecule.
By actual observations it has been shown that ether, alcohol, many esters of the normal alcohols and fatty acids, benzene, and its halogen substitution products, have critical constants agreeing with this originally empirical law, due to Sydney Young and Thomas; acetic acid behaves abnormally, pointing to associated molecules at the critical point.Advertisement
The same difference attends the introduction of the methyl group into many classes of compounds, for example, the paraffins, olefines, acetylenes, aromatic hydrocarbons, alcohols, aldehydes, ketones and esters, while a slightly lower value (157.1) is found in the case of the halogen compounds, nitriles, amines, acids, ethers, sulphides and nitro compounds.
It is remarkable that the position of the halogen in the molecule has no effect on the heat of formation; for example, chlorpropylene and allylchloride, and also ethylene dichloride and ethylidene dichloride, have equal heats of formation.
An important nucleus-synthetic reaction is the saponification of nitriles, which may be obtained by the interaction of potassium cyanide with a halogen substitution derivative or a sulphonic acid.
The advantage of the new definition lies in the fact that the estimation of the chlorine (or rather of the total halogen expressed as chlorine) is sufficient to determine the salinity by a very simple operation.
Eltekow, Ber., 1878, 11, p. 414); by the action of metals on the halogen compounds Cn.H 20 Br 2 i by boiling the aqueous solution of nitrites of the primary amines (V.Advertisement
Grignard (Comptes rendus, 1900 et seq.) observed that magnesium and alkyl or aryl halides combined together in presence of anhydrous ether at ordinary R temperatures (with the appearance of brisk boiling) to form compounds of the type RMgX(R = an alkyl or aryl group and X = halogen).
Chlor-, brom-, iodoand fluor-benzoic acids are known and can be obtained by oxidizing the corresponding halogen toluenes, or from the amido acids, or by substitution.
Nickel occludes hydrogen readily, is attacked by the halogen elements, and oxidizes easily when heated in air.
The word halogen is derived from the Greek as (sea-salt) and yevvav (to produce), and consequently means the sea-salt producer.
The halogen of lower atomic weight can displace one of higher atomic weight from its hydrogen compound, or from the salt derived from such hydrogen compound, while, on the other hand, the halogen of higher atomic weight can displace that of lower atomic weight, from the halogen oxy-acids and their salts; thus iodine will liberate chlorine from potassium chlorate and also from perchloric acid.Advertisement
The ketenes are usually obtained by the action of zinc on ethereal or ethyl acetate solutions of halogen substituted acid chlorides or bromides.
Compounds of antimony with all the halogen elements are known, one atom of the metal combining with three or five atoms of the halogen, except in the case of bromine, where only the tribromide is known.
It receives application in synthetic organic chemistry by virtue of its power to remove the halogen atoms from alkyl haloids, and so effect the combination of the two alkyl residues.
The tertiary phosphines are characterized by their readiness to pass into derivatives containing pentavalent phosphorus, and consequently they form addition compounds with sulphur, carbon bisulphide, chlorine, bromine, the halogen acids and the alkyl halides with great readiness.
The formation of addition compounds with the halogens, halogen hydrides, and with nitrosyl chloride, is characteristic of many, whilst others unite readily with nitrogen peroxide.
The haloid esters of the paraffin alcohols formed by heating the alcohols with the halogen acids are the monohaloid derivatives of the paraffins, and are more conveniently prepared by the action of the phosphorous haloid on the alcohol.
They do not possess basic properties; the halogen in the chlorine compounds is readily replaced by oxygen, and the oxides produced behave like basic oxides.
In its properties it shows some analogy to the halogen acids, since it forms difficultly soluble lead, silver and mercurous salts.
I have been running with halogen bulbs in my tail lights for about 12 years now.
The Cooking Pot has a solid base and is suitable for heating on all hobs, including ceramic and halogen cookers.
Internally the house benefits from brass halogen down lights throughout, and these are matched by brass dimmer switches and all electrical sockets.
This in turn involves bond dissociation, gain of an electron by the halogen, and hydration of the halide ion.
The site was lit by four halogen floodlights at the corners, an echo of the original guard towers of the PoW camp.
An aryl halide has a halogen atom attached directly to a benzene ring.
The ceiling is coved with recessed halogen down lights and there is a window above the sink overlooking the rear patio and garden.
Options are also available for fire retardant formulas including low smoke zero halogen.
A more reactive halogen can displace a less reactive halogen from an aqueous solution of its salt.
All you would need to do is swap the symbol Cl in the two equations for whichever other halogen you were interested in.
A tungsten halogen source may be better with auto white balance.
I am going to attempt this, for the first time ever, with a 500 watt quartz halogen bulb!
Don't confuse low energy bulbs with low voltage halogen light bulbs.
Inset four ring halogen hob with extractor hood over.
The average low beam range of a regular halogen headlamp is approximately 40 meters.
The 612 Scaglietti's twin xenon projector headlights also offer a beam that is far superior to traditional halogen lights.
The test car was also fitted with optional adaptive halogen headlights, which see round corners for a worthwhile £ 250.
The most modern form of hob today is the induction or halogen hob.
It works with both normal incandescent lamps and electronic and magnetic low voltage halogen lamps.
Sources of such energy include lasers, arc discharge lamps, and tungsten halogen bulbs.
The light source was a halogen lamp used in the dental clinic, emitting mainly in the blue part of the spectrum.
Lined in ash & sapele with panel lights and halogen lighting throughout.
The lone pairs on the halogen atom interact with the delocalized Pi system, which strengthens the C-X covalent bond.
Artificial light is provided by three swiveling halogen ceiling mounted fittings and concealed pelmet fluorescent lighting beneath wall unit.
Stone floors imported from a distant land reflect the twinkle of numerous recessed halogen spotlights in the ceiling above.
Continue to use quartz tungsten halogen curing lights as plasma arc curing lights appear to confer no clinical advantage at the present time.
The abnormal specific heats of the halogen elements may be due to a loosening of the atoms, a preliminary to the dissociation into monatomic molecules which occurs at high temperatures.
They are crystalline solids, usually of a yellow colour, which do not unite with acids; they are readily converted into amino-azo compounds (see above) and are decomposed by the concentrated halogen acids, yielding haloid benzenes, nitrogen and an amine.
The microscope has an epi-illumination system, with rheostat controlled 6v 20 watt quartz halogen system with full bulb adjustment.
Comparing the reaction rates of primary, secondary and tertiary halogenoalkanes You would need to keep the halogen atom constant.
The type of floor lamps that would work best for task lighting are arc floor lamps, adjustable floor lamps, halogen floor lamps and multiple light floor lamps.
Taking photos in rooms with halogen bulbs (twisted type bulbs) gets rid of the yellow glow.
Halogen gas and a regular light bulb filament combine in a quartz envelope to create a high-wattage, yet still cost-effective light source.
Most use high-intensity halogen bulbs, so even though the individual lights are quiet small, the beam is penetrating.
Low Voltage, Energy-Efficient Heads - New are low-voltage halogen lamps and heads that can be changed for your existing heads.
Enhance the features of your modern home with bright halogen light infused through a Swarovski crystal.
Transformers are easy to replace, but this will add to your maintenance cost over the years, as will the cost of using halogen bulbs, common in most track heads.
Halogen accent lights-Place these accent lights under your kitchen cabinets and transform your kitchen from a drab, boring area to an eye-catching room bathed in warmth.
If you're not used to halogen, this type of light tends to be whiter and brighter than some of the indoor light bulbs you may be using now.
If you need bright, clean light with flexible placement within your home, consider using halogen track lighting.
Halogen bulbs burn brighter and longer than traditional bulbs and with track placement, can give you that light right where you need it.
As old fashioned light bulbs begin to fall into disfavor, other types of light bulbs are beginning to come into popular use, including halogen light bulbs.
Halogen light bulbs produce a bright, white light that doesn't diminish over time the way traditional light bulbs do.
Additionally, halogen lights are up to 20 percent more energy efficient, while lasting nearly twice as long.
Add in the flexible placement of a halogen track lighting system, and you have a great light source for home offices, crafting rooms, living rooms and kitchen work areas.
There are several reasons why track lights, including track lights which use halogen bulbs, can be beneficial to homeowners.
Track lighting that uses halogen bulbs does have many pluses for homeowners.
Halogen lighting can produce a strong glare, particularly when pointed directly at a reflective surface.
Halogen bulbs burn very hot; so take care to choose lighting systems that shield the bulb to help prevent fires.
While a halogen bulb will last twice as long as a standard bulb, and reduce your energy costs by as much as 20 percent, they cost nearly four times as much as a standard bulb.
Make sure you do the math, and consider the other benefits of using halogen lights in your home before you purchase to make sure you are truly getting your money's worth.
There is no doubt that halogen track lighting is the work horse of home lighting options.
One potential drawback to using low voltage fixtures is that most of them employ halogen bulbs.
Halogen lighting is energy efficient, but may take some getting used to.
Halogen lights provide bright, white illumination that can cause eyestrain.
Another consideration is the added heat halogen lighting contributes to a room.
Light blue lenses on safety goggles are the right choice for jobs where the work space is being lit by fluorescent or halogen lighting.
Select GE models utilize Advantium Speed-Cook technology, which uses a halogen bulb.
The vacuum also has a halogen light system, which makes it easier to see when you're vacuuming under beds and chairs.
Considering derivatives primarily concerned with transformations of the hydroxyl group, we may regard our typical acid as a fusion of a radical R CO - (named acetyl, propionyl, butyl, &c., generally according to the name of the hydrocarbon containing the same number of carbon atoms) and a hydroxyl group. By replacing the hydroxyl group by a halogen, acid-haloids result; by the elimination of the elements of water between two molecules, acid-anhydrides, which may be oxidized to acid-peroxides; by replacing the hydroxyl group by the group. SH, thio-acids; by replacing it by the amino group, acid-amides (q.v.); by replacing it by the group - NH NH2, acid-hydrazides.
Other parts are halogen bulbs that help to cook food more quickly.