Structures Of Alkanes

An alkane is an acyclic saturated hydrocarbon in organic chemistry, commonly known as paraffin (a historical term with several meanings). An alkane is made up of hydrogen and carbon atoms that are organised in a tree structure with single carbon–carbon bonds.  The chemical formula of alkanes is C_nH_2n+2. The alkanes range in complexity from the simplest example of methane (CH₄) (often referred to as the parent molecule) to arbitrarily massive and complicated compounds like pentacontane (C₅₀H₁₀₂) or 6-ethyl-2-methyl-5-(1-methylethyl) octane, an isomer of tetradecane (C₁₄H₃₀).

In an alkane, each carbon atom has four sigma bonds (C–C or C–H), and each hydrogen atom is attached to one of the carbon atoms (in a C–H bond). The carbon skeleton, also known as the carbon backbone, is a molecule’s longest string of interconnected carbon atoms. An alkane’s size is determined by the number of carbon atoms in it.

Alkanes are mostly obtained commercially from petroleum (crude oil) and natural gas.

Structure of Alkanes

C_nH_2n+2 is the general formula for alkanes. An alkane containing 2(n) carbon atoms, for example, will have 6 (2n + 2) hydrogen atoms. Sigma bonds unite their neighbouring atoms, forming tetrahedral centres surrounding the carbon atoms. Because these are all single bonds, all connections are free to rotate. Each hydrogen atom is connected to a carbon atom by four bonds (either C-H or C-C bonds) (H-C bonds). 

Alkanes, commonly known as paraffins, are a kind of hydrocarbon that is entirely hydrogen-saturated. They have the  carbon and hydrogen which are connected covalently since they have no double or triple bonds in their carbon skeletons. Alkenes and alkynes, on the other hand, have double and triple bonds and are classified as unsaturated hydrocarbons.

It’s possible that the structural formula for alkanes might be stated in a more compact manner. Pentane, for example, has three groups of CH₂ methylene in the middle section of its structural formula. It’s possible to join them together and write down the structural formula. Below are the first five alkane formula with an unbranched chain:

Organic compound formulas include information on the compounds’ various characteristics and structures. The number and kinds of atoms in a molecule of a substance are determined by molecular formulae, such as the one for octane. C₈H₁₈ is a molecular formula that may be used for a variety of alkanes, each with its own set of physical, chemical, and toxicological characteristics. Structural isomers of a chemical are compounds having the same molecular formula but different structural formulae. Alkanes may now be used to extract a wide range of chemical molecules. Furthermore, many key components of organic compounds have one or more alkane groups. Many organic compounds have names derived from alkanes as a result of these reasons.

Types of Alkanes and Examples

Alkanes come in three different chemical structures: linear, branching, and cyclic. We’ll describe each kind and provide examples in this section.

The carbons in linear alkanes are bound together in a snake-like chain structure. Some examples of linear alkanes are included in the table below. Let’s look at decane as an example. There are two ways to depict the chemical structure. It can be represented with all of the carbon and hydrogen atoms visible, or as a chain (without the hydrogen atoms), with each edge representing a carbon atom.