What are Straight-Chain Hydrocarbons?

Alkanes are the straight chain hydrocarbons and have molecular formulas that fulfill${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}{}_{\text{+ 2}}$, the hydrocarbons having all links single bonds and where n is an integer. Carbon is hybridized by ${\text{sp}}^{\text{3}}$where the bonding is carried out by three electron pairs, which form a tetrahedral complex and the bond is each $\text{C-C}$and $\text{C-H}$sigma (σ).

Straight Chain Hydrocarbons 

Methane$\left({\text{CH}}_{\text{4}}\right)$, ethane $\left({\text{C}}_{\text{2}}{\text{H}}_6\right)$and propane $\left({\text{C}}_3{\text{H}}_8\right)$are the three primary elements of the class straight chain alkanes for the increasing carbon number.

The only alkanes that are distinct in their chemical structure are methane, ethane and propane. Two separate alkanes meet chemical coupling rules for $\left({\text{C}}_4{\text{H}}_{10}\right)$where the carbon has four bonds and hydrogen has only one. One compound, called n-butane, with a prefix n known as normal, is bound in a continual chain to its four carbon atoms. The other one has a branched chain, called isobutane. These two forms are referred to as isomers. Isomers are various molecules with the same molecular formula but different structural representation. The isomers which vary in the order in which the atoms are bound shall be called constitutional isomers which are said to have various conformations also known previously as structural isomers.

The n-butane as well as isobutane derivatives are constitutional isomers that can only be used for formulation $\left({\text{C}}_4{\text{H}}_{10}\right)$. Due to the fact that isomers are distinct molecules, they can be physically and chemically different. The boiling point is $\text{31}\text{.1°F}$ for n-butane is greater than that is for isobutane$\text{10}\text{.9 °F}$.

The carbon atoms in a formulation and the number of isomers are not simply an integer association. The principle of graph was used to quantify the potential quantity for n values in ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}{}_{\text{+ 2}}$from $\text{1 to 400}$, of constitutionally isomeric alkanes. With the carbon atoms, the number of constitutional isomers is increasing dramatically. The number of potential carbon molecules in hydrocarbons is certainly not higher. A thousand carbon atoms, including polyethylene, polypropylene and polystyrene, are bound tightly in hydrocarbon polymer chains.

Nomenclature 

The requirement to identify each compound needs a richer number of words than informative prefixes like n and iso. The identification of organic molecules is made easier by the use of systematic nomenclature schemes. The organic chemistry nomenclature has two types: traditional and systematic. Common names arise in many forms, but share the characteristic that a link through name and form is unnecessary. The name that matches a certain structure clearly must be remembered as knowing a person's name. In contrast, systemic names, including an overall common set of laws, are locked specifically to the chemical structure. 

According to the carbon count, IUPAC guidelines give names for unbranched alkanes. For ${\text{CH}}_{\text{4}}{\text{, CH}}_{\text{3}}{\text{CH}}_{\text{3}}$and ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$ methane, ethane and propane are maintained. The straight chain ${\text{CH}}_{\text{3}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{2}}{\text{CH}}_{\text{3}}$is known as butane, and not n-butane. The IUPAC systematic nomenclature has an n prefix. The name of the unbranched alkanes begins with five carbon chains, and consists of a Latin or Greek stem, which corresponds to the chain of carbon, proceeded by a —ane suffix.

The IUPAC systematic nomenclature has an n prefix. The name of the unbranched alkanes begins with five carbon chains, and consists of a Latin or Greek stem, which corresponds to the chain of carbon, proceeded by a —ane suffix. 

Three-Dimensional Structures 

Many organic compounds, like alkanes, are not flat, but rather three-dimensional. For instance, methane has the form of a regular tetrahedron centered with carbon and at every edge there is a hydrogen atom. The angle H―C―H angle in methane is $109.5°$and any width C/H bonding is$\text{1}\text{.09 Å}$. Higher alkanes, including butanes, have tetrahedral bonds, so that the subsequent angles of C-C and of H-C, respectively, are marginally bigger and shorter than just an optimal tetrahedron value of $109.5°$. The lengths in alkanes of carbon relation are typically about$1.53°$.

The non-identical organization of the atoms, created by the movement around single bonds, is a significant feature of the three-dimensional structure of alkanes and some other organic molecules. The eclipsed form of the ethane has the lowest stability and the phased structure is perhaps the most stable of all possible conformations—which are associated with the small changes in the movement of one ${\text{CH}}_{\text{3}}$group in relation to another. The eclipsed structure has been reported to be torsional due to the repulsive energy in the C—H bonds of adjoining carbons around the electron pair.

Cycloalkanes 

Countless organic compounds are believed to form a ring instead of being linked in a chain by a series of carbon atoms. Cycloalkanes are regarded to as saturated hydrocarbons which involve one ring. They have two less hydrogen atoms as compared to an alkane with the same number of carbon atoms, with a general formula of ${\text{C}}_{\text{n}}{\text{H}}_{\text{2n}}$where n is an integral higher than two. The smallest cycloalkane is the cyclopropane ${\text{(C}}_{\text{3}}{\text{H}}_{\text{6}}\text{)}$while the most research, understood and critical cycloalkane is cyclohexane ${\text{(C}}_{\text{6}}{\text{H}}_{\text{12}}\text{)}$. The study of cyclohexane was used to establish several of the critically fundamental concepts of morphological research. Three cyclohexane rearrangements are basically free from angle tension, identified as chair, boat, and skew or twist. The chair is quite secure of all three largely since it has a smooth structure of all its bonding.

Physical Properties 

Non polar compounds mostly comprise of the alkanes and cycloalkanes. The forces of London or the displacement factors resulting from molecular electron variation are attractive forces among alkane molecules and they are weak. Through comparison with polar modules with equal molecular mass, alkanes thus, have comparatively low boiling points. With the amount of carbons, the boiling points of the alkanes grow. This is since, though independently small, the intermolecular attracting forces grow collectively larger as the numbers of atoms including electrons rises in the compound. 

Chemical Reactions 

Alkanes are used to generate ${\text{CO}}_{\text{2}}$and water and emit heat, as is the case with all hydrocarbons. It is essential for their common utilization as fuels because all hydrocarbon products are exothermic. Gasoline grade is graded by evaluating its preignition value or the comparison mixes of heptane and 2,2,4-trimethylpentane and the assignment of octane numbers.

Common Mistakes 

The most common mistake a student can do is in counting the number of carbon atoms and numbering it.  

Context and Applications 

This topic is significant in the professional exams for both undergraduate and graduate courses, especially for Bachelors and Masters in Chemistry.