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alkene , any of a group of aliphatic hydrocarbons whose molecules contain one or more carbon-carbon double bonds (see chemical bond ). Alkenes with only one double bond have the general formula C n H 2n . In the International Union of Pure and Applied Chemistry (IUPAC) system of chemical nomenclature, the name of an alkene is derived from the name of the corresponding alkane by replacing the - ane alkane suffix with - ene and, if necessary, adding a prefix to indicate the location of the double bond in the molecule. The IUPAC name of the simplest alkene, H 2 C[symbol]CH 2 , is ethene, which is derived from ethane. Propene is related to propane. Two alkenes, 1-butene and 2-butene, are related to butane; these two compounds, which differ in the location of the double bond in their molecules, are structural isomers . In addition to these IUPAC names, many of the alkenes have common names, e.g., ethene is called ethylene and propene propylene. The alkenes as a group are sometimes called the ethylene series. Since the carbon-carbon double bond is sometimes called an olefinic linkage, the alkenes are sometimes called the olefins. Many of the reactions in which alkenes take part involve the cleavage of half the carbon-carbon double bond and subsequent formation of two single bonds, one to each of the adjacent carbon atoms. Such reactions include hydrogenation, with the formation of an alkane, and hydration, with the formation of an alcohol.

From Omilili

Sta-bil Marine & Seafoam

Of the alkene class of hydrocarbons, and it is also second in natural abundance. Propene is the raw for a chemical compound with the molecularformula C3H8O Isopropyl alcohol is produced by combining water . This information is straight from their websites...: Marine Formula STA-BIL Ethanol Treatment

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Question:Does anyone have any information on the history of Aldehydes, not the history of the Aldehyde-Schiff reactions, of Aldehydes.

Answers:Aldehydes are a class of highly reactive organic chemical compounds that contain a carbonyl group (in which a carbon atom is double-bonded to an oxygen atom) and at least one hydrogen atom bound to the alpha carbon (the central carbon atom in the carbonyl group). The aldehydes are similar to the ketones, which also contain a carbonyl group. In the aldehydes, however, the carbonyl group is attached to the end of a chain of carbon atoms, which is not the case with the ketones. The name aldehyde was given to this group of compounds in the nineteenth century by German chemist Justus von Liebig (1803-1873) and was taken from a mock Latin phrase, alcohol dehydrogenatus, describing their preparation. (The first aldehyde was prepared by removing two hydrogen atoms (dehydrogenation) from ethanol.) The general formula for an aldehyde is RCHO, with R representing an alkyl group. The names of specific aldehydes are generally taken from the name of the alkyl group with the addition of an "-al" ending, e.g. methanal, ethanal. Aldehydes are generally colorless liquids or (for those with a ring structure) solids. They can be prepared from the oxidation of primary alcohols. The CHO group of the aldehydes does not form hydrogen bonds, unlike the OH group of the alcohols. As a result, the boiling points of aldehydes are considerably lower than the boiling points of corresponding alcohols. For example, menthanol boils at 150.8 F (66 C) and methanal (formaldehyde) boils at -5.8 F (- 21 C). Most aldehydes are soluble in water; their solubility decreases as their molecular weight increases. Aldehydes are very easy to detect by smell. Some are very fragrant, and others have a smell resembling that of rotten fruit. Aldehydes have a strong tendency to join together to produce polymers. This makes the whole group very important in the manufacture of plastics, and they react quite readily with a large number of other molecules by simple addition. Aldehydes can be converted to alcohols by the addition of two hydrogen atoms to the central carbon oxygen double bond (reduction). Oxidation of an aldehyde breaks the double bond within the carbonyl group to give a carboxylic acid. Aldehydes also readily undergo substitution reactions with halogens. If chlorine gas is bubbled through ethanal, the hydrogen atoms of the methyl group are replaced by chlorine atoms to give chloral. Chloral is a strong hypnotic and is also the first step in the manufacture of DDT, carbon tetrachloride. Chloroform, and silicone rubbers. Methanal (formaldehyde) is the simplest aldehyde. The central carbon atom in the carbonyl group is bound to two hydrogen atoms. Its chemical formula is H2C=O. Methanal, discovered by Russian chemist Aleksandr Butlerov in 1859, is a gas in its pure state. It is either mixed with water and sold as formalin solutions or as a solid polymer called paraformaldehyde. The rather small methanal molecule is very reactive and has found applications in the manufacture of many organic chemicals such as dyes and medical drugs. Methanal is also a good insecticide, and it is used to kill germs in warehouses and ships. It is probably most familiar to the general public in its application as a preservative. In biological laboratories, animals and organs are suspended in formaldehyde solutions, which are also used as embalming fluid to preserve dead bodies from decay. Ethanal (acetaldehyde) is the name of the shortest carbon chain aldehyde. It has a central carbon atom that has a double bond to an oxygen atom (the carbonyl group), a single bond to a hydrogen atom, and a single bond to another carbon atom connected to three hydrogen atoms (methyl group). Its chemical formula is written as CH3CHO. Ethanal is one of the oldest known aldehydes and was first made in 1774 by Swedish chemist Carl Wilhelm Scheele (1742-1786). Its structure was not completely understood until 60 years later, when Justus von Liebig determined the constitution of ethanal, described its preparation from ethanol, and gave the name of aldehydes to the chemical group. The next larger aldehyde molecules have longer carbon atom chains with each carbon atom connected to two hydrogen atoms. This group of aldehydes is called aliphatic and has the general formula CH3(CH2)nC HO, where n=1-6. When n=1, the aldehyde formula is CH3CH2CHO and is named propanal (propionaldehyde); when n=2, CH3(CH2)2C HO or butanal (butyraldehyde). The aliphatic aldehydes have irritating smells. For example, the smell of butanal, in low concentrations, resembles that of rotten butter. These medium-length aldehyde molecules are used as intermediates in the manufacture of other chemicals such as acetone and ethyl acetate used in nail polish remover. They are also important in the production of plastics. Fatty aldehydes contain long chains of carbon atoms connected to an aldehyde group. They have 8-13 carbon atoms in their molecular formula. The fatty aldehydes have a very pleasant odor, with a fruity or a floral scent, and can be detected in very low concentrations. Because of these characteristics, the fatty aldehydes are used in the formulation of many perfumes. They are also added to soaps and detergents to give them their "fresh lemon scent." The aromatic aldehydes have a benzene or phenyl ring connected to the aldehyde group. The aromatic aldehyde molecules have very complex structures but are probably the easiest to identify. The odor of cinnamon found in various products is due to an aromatic aldehyde of complex structure named 3-phenyl-2-propenal (cinnamaldehyde). Another aldehyde, 4- hydroxy-3-methoxy-benzaldehyde (vanillin), is a constituent of many vanilla-scented perfumes.


Answers:"Methene" (C1) does not exist. C2 = Ethene, colorless gas at RT, mp = -169 deg C, bp = -104 deg C, flammable, non polar, slightly sweet smelling, soluble in non polar solvents only C3 = Propene, colorless gas at RT, mp = -185 deg C, bp = -47 deg C, small dipole moment due to reduced symmetry C4 = But-1-ene (there are other forms of butene, each has different properties), colorless gas at RT, flammable, mp = -185 deg C, bp = -6 deg C C5 = 2-pentene, flammable liquid, mp -140 deg C, bp = 37 deg C C6 = 1-hexene, colorless liquid, mp = -139, bp = 63 deg C You can find the molecular formula for all of the alkenes and all of the above-mentioned alkenes are soluble in non polar solvents only. Hope that helps

Question:In a chemical like Butene how do you know that there is a double bond?

Answers:In chemistry we generally use 3 kinds of bonds -> 1. single bond represented by single line (-) 2. double bond represented by double lines (=) 3. triple bond represented by triple lines ( ) and we know that when 2 use single, double, and triple bond are depend upon name of any compound. for eg. if name of any compound ends with "-ane" (butane, propane) we use single bonds b/w them CH3-CH2-CH2-CH3. compounds ends with "- ene" ( propene, hexene, heptene) we use double bond CH2=C=CH2 and at last compounds ends with "-yne" we use triple bond CH CH . These rules on;y work for hydrocarbon compounds. Hydrocarbons are te compounds that contain carbon and hydrogen. and hydrogen have 4 valancy i.e it can form ony 4 bonds. so the formula of butene has 4 caron and 8 hydrogen coz 8 hydrogens cant fulfil the all valency of carbon hence there will be a double bond to complete the valency of carbon. Hope it will make sense. cheers!

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