Hydrocarbons

Introduction

Organic compounds such as hydrocarbons comprise only hydrogen and carbon atoms. They are group 14 hybrids containing hydrogen and group 14 carbon atoms; carbon, silicon, germanium, tin and lead. Carbon has 4 electrons, so it has to form exactly 4 bonds to be stable. Another class of hydrocarbons are aromatic hydrocarbons, including alkanes, naphthenes, and alkyne-based compounds. Hydrocarbons can form more complex compounds such as cyclohexane by combining with themselves. This is called chaining.

What are Hydrocarbons?

In organic chemistry, a hydrocarbon is an organic compound made entirely of hydrogen and carbon, hence they are Group 14 hydride. A hydrocarbon with one hydrogen atom removed is a functional group called a hydrocarbyl. Aromatics hydrocarbons (arenes), alkanes, alkenes, cycloalkanes, and alkyne-based compounds are different types of hydrocarbons. Most hydrocarbons found on Earth are naturally present in crude oil, where decomposing organic matter produces large amounts of carbon and hydrogen that, when combined, can work together to form seemingly infinite chains.

Types of Hydrocarbons

Apart from alcohols, aldehydes and carboxylic acids, hydrocarbons are the simplest organic compounds and can be divided into the following categories:

1. Saturated Hydrocarbons

Saturated hydrocarbon compounds contain only C-C single bonds, and all carbons in them are fully utilised. It is less reactive. Alkanes are saturated hydrocarbons.

Alkanes

These are singly bonded, when n=1 (only one carbon atom). Methane, CH4 are examples of alkanes. When n=2, each carbon forms 4 covalent bonds and forms C2H6. Likewise, C3H8 is formed; all these compounds (methane, ethane, and propane, respectively) are alkanes. Hence, the formula for alkanes is CnH(2n+2).

Many carbon atoms derive the names for organic compounds, where the presence of one carbon atom refers to meth, 2 is eth, 3 is prop, 4 is buy, 5 is pent, 6 is hex, 7 is hept, 8 is oct, and 9 is non, and the presence of 10 carbon atoms means dec.

2. Unsaturated Hydrocarbons

Here at least two carbon atoms are linked by double or triple bonds.

Unsaturated hydrocarbons are more reactive because double and triple bonds are easily broken and added. Alkenes and alkynes are two unsaturated hydrocarbons, where alkenes contain at least one double bond and alkynes contain at least one triple bond.

Alkenes

These compounds have double bonds. If n = 1, we have no valid alkene. When n=2, C2H4 (ethene) is produced, and when n=3, C3H6 (propene) is produced. Hence, the formula for alkenes is CnH(2n) .

Alkynes

They are also unsaturated hydrocarbons with triple bonds. It is not a valid alkyne when n=1; it forms C2H2 (ethyne) when n=2, and C3H4 (propyne) when n=3. Hence, the formula of an alkyne is CnH(2n-2) . All alkynes have the suffix “yne”. The suffix is “ene” for alkene, and “ane” for alkane.

3. Cyclic or Closed Hydrocarbons

Cyclic hydrocarbons are hydrocarbons in which carbon chains are linked themselves into rings. All carbon-carbon bonds are single bonds in a cyclic hydrocarbon. Like other alkanes, naphthenes are saturated compounds. Cycloalkanes have the general formula CnH2n. The simplest cycloalkane is cyclopropane, which is a ring with three carbon atoms.

Examples-  Cyclohexane is a six-carbon cycloalkane, cyclopropane, the simplest cycloalkanes.

Example of Hydrocarbons

Methane and propane are gaseous hydrocarbons, hexane and benzene are liquid hydrocarbons,  paraffin wax and naphthalene are hydrocarbons with low melting points, and polystyrene, polypropylene and polyethylene are polymeric chain hydrocarbons.

Uses of Hydrocarbons

Hydrocarbons have a number of uses. Some of them are as follows:

1. These are used as fuel sources such as methane (a component of natural gas).

2. Gasoline, jet fuel, and naphtha are aliphatic hydrocarbons widely used in various industries.

3. Roofing compounds, bitumen or pavement compositions and wood preservatives are also different forms of hydrocarbons.

4. Their applications as large-scale non-fuels such as ethane and propane are derived from oil and natural gas. These two gases can then be converted into ethylene and propylene.

5. Natural hydrocarbons are found in Brazilian stingless bees, and they leave a distinctive hydrocarbon odour that helps distinguish kin from non-kin.

Conclusion

Hydrocarbons are the simplest organic compounds, containing only carbon and hydrogen, but they can be straight or branched, with the same empirical formula but different properties. Chemical changes result in hydrocarbons that produce products that may be completely different in composition from the starting hydrocarbons—except for isomerisation reactions in which straight-chain hydrocarbons are converted to branched-chain hydrocarbons.

The chemical properties of hydrocarbons show the ability of hydrocarbons to undergo chemical changes or reactions through the hydrocarbon structure. The physical properties of hydrocarbons can be perceived or measured without changing the composition of matter. Physical properties are used to outline and perceive substances. Physical properties of interest in the current context include boiling point, melting point, specific gravity, vapour density, flash point, ignition temperature, and dew point.