nalkanen

N-alkanen, also known as normal alkanes or n-alkanes, are a family of acyclic saturated hydrocarbons with the general formula CnH2n+2, where n is a positive integer. They consist solely of carbon and hydrogen connected by single bonds, with all carbon atoms sp3 hybridized in a continuous straight-chain arrangement, i.e., unbranched.

In nomenclature, the prefix “n-” denotes an unbranched chain. The series forms by adding CH2 units to the end of the chain, yielding members such as methane (CH4), ethane (C2H6), propane (C3H8), and butane (C4H10). For higher n, numerous isomers exist, but these are branched alkanes rather than true n-alkanes.

Physical properties of n-alkanes include nonpolarity, low water solubility, and a gradual increase in boiling point with increasing chain length. Methane is a gas at room temperature, while heavier members are liquids or solids. Densities are typically less than water for lighter members.

Chemical properties are characterized by relative inertness under standard conditions. They undergo combustion in oxygen to carbon dioxide and water. Under ultraviolet light, they can participate in free-radical halogenation and other substitution reactions, though these are generally slower than for unsaturated hydrocarbons. They do not readily react with most inorganic acids or bases.

Occurrence and applications: n-alkanes occur naturally in natural gas and crude oil and are separated by distillation and further processing. They serve as fuels and as feedstocks for the chemical industry, providing starting materials for many products.

Environmental and safety notes: alkanes are flammable and can pose fire and explosion hazards. Methane is a potent greenhouse gas; combustion releases carbon dioxide and water.