Hydrocarbons are any in the class of organic chemical compounds created solely of the elements carbon and hydrogen. The carbon atoms join together to form the framework of the compound; the hydrogen atoms join to them in lots of varied configurations. Hydrocarbons are the elementary constituents of petroleum and natural gas. They can be fuels and lubricants as well as raw materials for the creation of plastics, fibres, rubbers, solvents, explosives, and industrial chemicals.
Many hydrocarbons occur in nature. As well as forming fossil fuels, hydrocarbons are part of trees and plants, as, for example, for the form of pigments called carotenes that can be found in carrots and green leaves. More than 98 percent of natural crude rubber is a part of hydrocarbon polymer, a chainlike molecule that consists of many units connected.
Hydrocarbons are insoluble in water and they are less dense than water, so they will float on the top. They will mostly be soluble within one another, however, as well as with certain organic solvents. All hydrocarbons are combustible. If they are burned completely with an adequate amount of oxygen, they should produce carbon dioxide and water, releasing heat. If there is inadequate oxygen, the combustion will form carbon monoxide.
The structures and chemistry of single hydrocarbons is dependant in large part on the sorts of chemical bonds that link the atoms of their constituent molecules. A carbon atom might have four single bonds, or double or triple bonds. A hydrogen atom may feature a single bond.
Hydrocarbons are categorized within several classes according to their structure. The two major categories are aliphatic and aromatic. Aliphatic hydrocarbons might be formed out of molecules in which the carbon atoms are attached in chains (called acyclic) or in rings (termed alicyclic, or carbocyclic). Aliphatic hydrocarbons will be also divided into categories depending on the kind of bonds between the carbon atoms. For aliphatic hydrocarbons, if each bond is single (termed sigma bonds), the compound is said to be saturated. Those compounds are classified as alkanes or cycloalkanes. If at least two bonds combine any two carbon atoms, the hydrocarbon is called unsaturated. The bonds may be double, like for the alkenes or alkadienes, or triple, as in the alkynes. Some compounds possess both classes of multiple bonds within the single molecule.
The simplest alkanes are methane, ethane , and propane. Those compounds can exist in only a single structure for each. Higher members of the series, beginning with butane, can be compounded in two varying ways, according to whether the carbon chain is straight or branched. They compounds are called isomers; they are compounds with the identical molecular formula but then have different arrangements of the atoms. Because of this, they frequently have varied chemical properties.
Cycloalkanes are ring structures featuring two fewer hydrogen atoms inside the molecule of the corresponding alkane. Lots of these possess multiple rings, not just one. Six-membered rings are of particular interest because of the fact that they can be seen in many natural products, particularly the steroids. Cyclic structures also may be isomers in the case where two molecules differ only in the spatial arrangement of substituent groups.
The basic commercial sources of alkanes are petroleum and natural gas. Particular higher alkanes and cycloalkanes commonly are synthesized with reactions designed for a specific product. These saturated hydrocarbons may also be synthesized by corresponding unsaturated molecules, by hydrogenation (addition of hydrogen). Saturated hydrocarbons are largely inert; i.e., in room temperature they will be unaffected by common acids, alkalies, and oxidizing or reducing agents.