Hydrocarbons are usually a mixture of hydrogen and carbon. Organic chemistry deals with such hydrocarbons that can be divided into two classes namely – Aromatic and Aliphatic compounds. An organic compound that contains the combination of carbon and hydrogen that are joined together in a straight line, non-aromatic rings or branched chains is termed as Aliphatic Compound. The aliphatic compounds are therefore non-aromatic in nature. The compound therefore contains simple chains of carbon, ketones, carboxylic acids, alkanes, alkenes, aldehydes, alcohol, halides, amines and so many more. The aliphatic compounds can also be cyclic in nature. In case there is a unique cyclic structure that is there exists a stable cyclic bond in the molecule (the benzene ring), then the compound becomes an aromatic compound. Some examples of the aliphatic compound are – Acetylene, propane, isooctane, propene, ethylene, propane, polyethylene and squalene. These compounds are also termed as eliphatic compounds or aliphatic hydrocarbons.  

One of the most important properties of the aliphatic compound is that this compound is usually flammable in nature and hence used as fuel. This compound is used for several industrial purposes. They are – Chemical intermediates, solvents, metal-cleaning agents, paint and varnishes, textiles, pharmaceuticals, plastics, dye, dry calling as well as fire extinguishing compounds.  Aliphatic compounds can be structured as Saturated and Unsaturated.  The structured compounds are joined by single bonds like the alkanes. The unstructured compounds on the other hand are joined by bonds that are double (Alkenes) or triple (Alkynnes) in nature. The compound combination contains many other elements other than only hydrogen. These elements are mostly oxygen, chlorine, nitrogen and sulfur. These combination of elements form several different complex compounds. The compound that is among one of the least complex aliphatic compound is methane (CH4).

The aliphatic compounds undergo various types of reactions that can be divided into substitution and elimination. The substitution reaction refers to the type of chemical reaction that includes the replacement of atoms or any functional group of the molecules by other atom or functional group of molecules. It also refers to a single substitution or a single replacement reaction. If a CH3Cl (Chloromethane) reacts with a hydroxyl ion (OH-), then it will replace the chlorine atom with the hydroxide ion and will produce CH3OH (Methanol) and Chlorine separately. The substitution method can be again divided into three broad categories that depends on the type of the atom or molecule groups that acts as the substituent of the reaction. The three divisions are nucleophilic substitution, electrophilic substitution and the reactions of the free radicals. In case of neucleophilic substitution, one of the substituent is rich in electron and allows the electron pair to bond with the substrate. In case of an electrophilic substitution, one of the substituent lacks electrons and the pair of electron for bonding with the substrate is derived from the substrate itself. The third type includes the reaction of the free radicals with their suitable substrates.

The elimination reaction on the other hand refers to that chemical reaction, which includes the elimination of atom, pair or group of atoms from a molecule. The elimination is usually processed through the actions of acids, bases, metals and in certain cases heating at a high temperature. It is the process where the number of the carbon compounds are doubled or tripled that is the compounds become unsaturated from a saturated compound. The elimination reaction can be again divided into – dehydrohalogenation, dehydration and dehydrogenation.  When the hydrogen atom and halogen atom is removed, it is called as dehydrohalogenation, when halogen atom is removed it is called as dehalogenation, when water molecule is removed from alcohol, it is called as dehydration and when both the leaving atoms are hydrogen it is termed as dehydrogenation.