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hydrocaons

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Methane is a very powerful greenhouse gas. One pound of methane traps 25 times m ore heat in the atmosphere than a pound of carbon dioxide. Methane is also the m ain ingredient in natural gas. Because methane can be captured from landfills, i t can be burned to produce electricity, heat buildings, or power garbage trucks. Methane is used (i) As a fuel for domestic and industrial purpose because it produces large amou nt of heat and leaves no ash on burning. (ii) For the manufacture of carbon black. Carbon black is used for making paints , black printing ink etc. (iii) For the preparation of methanol (methyl alcohol), methanol (formaldehyde),  chloromethane (methyl chloride) etc. Ethene is usd to accelerate the ripening of fruits ad is mostly used on bananas and also on some Citrus fruits.The other use of ethane is in the manufactureof p lastics, such as packin films, ire coatings and squeeze ottles. Pentanes are some of the primary blowing agents used in the production of polyst yrene foam and other foams. Usually, a mixture of n-, i-, and increasingly cyclo pentane is used for this purpose. Because of its low boiling point, low cost, an d relative safety, pentane is used as a working medium in geothermal power stati ons. It is added into some refrigerant blends as well. Pentanes are also used as  an active ingredient in some pesticides.Pentanes are relatively inexpensive and  are the most volatile alkanes that are liquid at room temperature, so they are often used in the laboratory as solvents that can be conveniently evaporated. Ho wever, because of their nonpolarity and lack of functionality, they can only dis solve non-polar and alkyl-rich compounds. Pentanes are miscible with most common  nonpolar solvents such as chlorocarbons, aromatics, and ethers. They are also o ften used in liquid chromatography. Hexane In industry, hexanes are used in the formulation of glues for shoes, leather pro ducts, and roofing. They are also used to extract cooking oils (such as canola o il) from seeds, for cleansing and degreasing a variety of items, and in textile manufacturing. A typical laboratory use of hexanes is to extract oil and grease contaminants fr om water and soil for analysis.Since hexane cannot be easily deprotonated, it is  used in the laboratory for reactions that involve very strong bases, such as th e preparation of organolithiums. For example, butyllithiums are typically suppli ed as a hexane solution.In many applications (especially pharmaceutical), the us e of n-hexane is being phased out due to its long term toxicity. It is often rep laced by n-heptane, which will not form the toxic metabolite hexane-2,5-dione. Butane Normal butane is mainly used for gasoline blending, as a fuel gas, either alone or in a mixture with propane, and as a feedstock for the manufacture of ethylene  and butadiene, a key ingredient of synthetic rubber. Isobutane is primarily use d by refineries to enhance (increase) the octane number of motor gasoline. When blended with propane and other hydrocarbons, it may be referred to commerci ally as LPG, for liquified petroleum gas. It is used as a petrol component, as a  feedstock for the production of base petrochemicals in steam cracking, as fuel for cigarette lighters and as a propellant in aerosol sprays such as deodorants

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Page 1: hydrocaons

8/9/2019 hydrocaons

http://slidepdf.com/reader/full/hydrocaons 1/2

Methane is a very powerful greenhouse gas. One pound of methane traps 25 times more heat in the atmosphere than a pound of carbon dioxide. Methane is also the main ingredient in natural gas. Because methane can be captured from landfills, it can be burned to produce electricity, heat buildings, or power garbage trucks.

Methane is used

(i) As a fuel for domestic and industrial purpose because it produces large amount of heat and leaves no ash on burning.

(ii) For the manufacture of carbon black. Carbon black is used for making paints, black printing ink etc.

(iii) For the preparation of methanol (methyl alcohol), methanol (formaldehyde), chloromethane (methyl chloride) etc.

Ethene is usd to accelerate the ripening of fruits ad is mostly used on bananasand also on some Citrus fruits.The other use of ethane is in the manufactureof plastics, such as packin films, ire coatings and squeeze ottles.

Pentanes are some of the primary blowing agents used in the production of polystyrene foam and other foams. Usually, a mixture of n-, i-, and increasingly cyclopentane is used for this purpose. Because of its low boiling point, low cost, and relative safety, pentane is used as a working medium in geothermal power stations. It is added into some refrigerant blends as well. Pentanes are also used as an active ingredient in some pesticides.Pentanes are relatively inexpensive and are the most volatile alkanes that are liquid at room temperature, so they areoften used in the laboratory as solvents that can be conveniently evaporated. However, because of their nonpolarity and lack of functionality, they can only dissolve non-polar and alkyl-rich compounds. Pentanes are miscible with most common nonpolar solvents such as chlorocarbons, aromatics, and ethers. They are also o

ften used in liquid chromatography.

HexaneIn industry, hexanes are used in the formulation of glues for shoes, leather products, and roofing. They are also used to extract cooking oils (such as canola oil) from seeds, for cleansing and degreasing a variety of items, and in textilemanufacturing.

A typical laboratory use of hexanes is to extract oil and grease contaminants from water and soil for analysis.Since hexane cannot be easily deprotonated, it is used in the laboratory for reactions that involve very strong bases, such as the preparation of organolithiums. For example, butyllithiums are typically suppli

ed as a hexane solution.In many applications (especially pharmaceutical), the use of n-hexane is being phased out due to its long term toxicity. It is often replaced by n-heptane, which will not form the toxic metabolite hexane-2,5-dione.

Butane

Normal butane is mainly used for gasoline blending, as a fuel gas, either aloneor in a mixture with propane, and as a feedstock for the manufacture of ethylene and butadiene, a key ingredient of synthetic rubber. Isobutane is primarily used by refineries to enhance (increase) the octane number of motor gasoline.

When blended with propane and other hydrocarbons, it may be referred to commercially as LPG, for liquified petroleum gas. It is used as a petrol component, as a

 feedstock for the production of base petrochemicals in steam cracking, as fuelfor cigarette lighters and as a propellant in aerosol sprays such as deodorants

Page 2: hydrocaons

8/9/2019 hydrocaons

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Octane"Octane" is colloquially used as a short form of "octane rating" (named for theability of octane's branched-chain isomers, especially isooctane, to reduce engine knock), particularly in the expression "high octane." However, components ofgasoline other than isomers of octane can also contribute to a high octane rating, while some isomers of octane can lower it, and n-octane itself has a negative octane rating

Propane use is growing rapidly in non-industrialized areas of the world. Propane has completely replaced wood and other traditional fuel sources, now it's commonly known as 'cooking gas'. The "propane" sold outside North America is actually a mixture of propane and butane. The warmer the country, the higher the butanecontent, commonly 50/50 and sometimes reaching 75% butane. Usage is calibrated to the different-sized nozzles found in non-U.S. grills.Propane is also instrumental in providing off-the-grid refrigeration, usually by means of a gas absorption refrigerator.

Blends of pure, dry "isopropane" (R-290a) (isobutane/propane mixtures) and isobu

tane (R-600a) have negligible ozone depletion potential and very low Global Warming Potential (having a value of 3.3 times the GWP of carbon dioxide) and can serve as a functional replacement for R-12, R-22, R-134a, and other chlorofluorocarbon or hydrofluorocarbon refrigerants in conventional stationary refrigerationand air conditioning systems

Heptane (and its many isomers) is widely applied in laboratories as a totally non-polar solvent. As a liquid, it is ideal for transport and storage. In the grease spot test, heptane is used to dissolve the oil spot to show the previous presence of organic compounds on a stained paper. This is done by shaking the stained paper in a heptane solution for about half a minute.

Aqueous bromine may be distinguished from aqueous iodine by its appearance after

 extraction into heptane. In water, both bromine and iodine appear brown. However, iodine turns purple when dissolved in heptane, whereas the bromine solution remains brown.

Heptane is commercially available as mixed isomers for use in paints and coatings, as the rubber cement solvent "Bestine", the outdoor stove fuel "Powerfuel" by Primus, as pure n-Heptane for research and development and pharmaceutical manufacturing and as a minor component of gasoline.