Alkene - Formula, Definition, Classification, Properties & Uses of Alkene with Examples & Videos

Unsaturated compounds are referred to as alkenes. Alkenes, sometimes called olefins, are organic substances made up of carbon and hydrogen atoms with one or more double bonds connecting the carbon atoms in their chemical structure. An alkene's functional group is a carbon-carbon double bond. Because just carbon and hydrogen atoms make up hydrocarbons, alkenes are referred to as being unsaturated. This is because alkenes have fewer hydrogen atoms per carbon atom than is theoretically conceivable. Alkenes are more reactive than alkanes because of the double bond present in them. Ethene, also called ethylene, is an example of an alkene chemical.

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This Story also Contains

1. Overview
2. Classification Of Alkenes
3. Structures Of Alkenes
4. Physical Properties Of Alkenes
5. Chemical Properties Of Alkenes
6. Uses Of Alkenes
7. Conclusion

Overview

A group of hydrocarbons are called alkenes. There is at least one carbon-carbon double bond among every member of this family. Instead of being found in significant amounts in crude oil, alkenes are discovered by cracking alkanes. The most pure alkene is ethene, and alkenes play a significant role in the chemical industry. Although ethene cannot be used as fuel on its own, it is utilised to create compounds such as plastics and other substances that can. Alkenes' chemical and physical characteristics, as well as their applications, will be covered in this article.

Classification Of Alkenes

The stability of the double bond depends on the alkyl groups attached to the alkenes' sp2 hybridised carbon atoms. The quantity of alkyl groups attached to the sp2 hybridised carbon atoms has a significant impact on the chemical reactivity of alkenes. As a result, it is helpful to categorise alkenes according to the quantity of alkyl groups connected to the C=C structural unit. The degree of substitution is the name of this characteristic.

A monosubstituted alkene is one in which the sp2 hybridised carbon atom of the double bond is joined to a single alkyl group. Another name for an alkene is a terminal alkene, which refers to an alkene whose double bond is at the end of the carbon atom chain.

Alkenes are classified as disubstituted, trisubstituted, or tetrasubstituted depending on how many alkyl groups there are attached to the double bond's carbon atoms.

Structures Of Alkenes

The only C-C single bonds found in an alkane make it the most basic hydrocarbon. The number of H atoms in chain alkanes reaches its maximum level, and the chain alkane fits the general formula of CnH2n+2 (n: positive integer).

Physical Properties Of Alkenes

Unsaturated hydrocarbons come in the shape of alkenes. Alkenes are flammable, colourless, and non-polar substances that have many physical characteristics with alkanes. Alkenes can have isomers because of their physical makeup. As they frequently have same or very similar boiling temperatures, isomeric alkenes are challenging to distinguish by boiling. Additionally, they exist in the gaseous, liquid, and solid states at room temperature, which is due to the carbon-carbon double bond. Because of their weak van der Waal forces, alkenes are lighter than water and insoluble in water. However, when alkenes come into contact with organic solvents, additional van der Waal forces form, making the alkenes soluble. Alkenes' boiling points are directly inversely correlated with their molecular structures; the longer the molecular chain, the higher the boiling point. Alkenes' boiling points are directly inversely correlated with their molecular structures; the longer the molecular chain, the higher the boiling point.

Chemical Properties Of Alkenes

Because they are unsaturated molecules, alkenes are very reactive chemically. Alkenes and alkanes are both flammable, but alkenes are often far more reactive than alkanes because the majority of the chemical processes inside of alkenes take place at the carbon-carbon double bonds. Alkenes typically undergo three main chemical reactions: first, when hydrogen is added, they become alkanes; second, when halogens are added, alkenes produce vicinal dihalides; and third, when hydrogen halides are added, the hydrogen attaches at the carbon-carbon double bond to the atom that is attached to more hydrogen atoms, and the halide ion attaches to the atom that is attached to fewer hydrogen atoms. The Markovnikov rule states that.

Uses Of Alkenes

Alkenes are very helpful to people, and they are utilised in many different industries to make a wide variety of goods. First, and maybe most significantly, they are used to make polythene. The plastic that is used to make several products, including plastic cups, plates, bowls, chairs, etc., is also made from polythene, which is also used to make polythene bags. Alkenes also produce ethane-1,2-diol, a substance utilised in automobile radiators as an anti-freezing agent. Alkenes and polystyrene are both used in the production of battery covers and radiator components for automobiles. Alkenes are used to create acrylic fibres. Alkenes are used to create polypropene, which is then utilised to create a plastic that is used to package a variety of goods as well as to create ropes. Propanol and acetone, sometimes known as nail polish remover and acetone, respectively, are made from alkenes and propanol, respectively. Alkenes are also utilised to create ethanol, or drinking alcohol, which is produced in the production of synthetic fibres.

Conclusion

Due to the many products that may be made utilising alkenes, this family of hydrocarbons is immensely significant and valuable to humans. Alkanes must be cracked in order to find them because they are not widely distributed. Since they always contain a carbon-carbon double bond, this greatly influences their chemical characteristics. Because of the double bond in the carbon atom, they have physical characteristics that are quite similar to those of alkanes and can exist at room temperature in solid, liquid, and gaseous forms.