The word "alkanes" is a term used in chemistry to describe a group of hydrocarbons that have only single bonds between carbon atoms. The spelling of this word is determined by the International Phonetic Alphabet (IPA), which represents individual sounds in words. In IPA, "alkanes" is spelled as /ælkeɪnz/, with the emphasis on the first syllable. The "a" is pronounced as in "cat," while the "e" is pronounced as in "bet." The "k" sound represents the "c" sound in "cat," which makes the word easy to remember.
Alkanes are a group of hydrocarbons consisting solely of carbon and hydrogen atoms, characterized by the presence of single covalent bonds. They are saturated hydrocarbons, meaning they contain the maximum number of hydrogen atoms bonded to carbon atoms without any carbon-carbon double or triple bonds. Alkanes are referred to as "straight-chain" or "linear" when their carbon atoms form a continuous chain without any branching. However, they can also have branching, referred to as "branched-chain" alkanes.
In terms of their physical properties, alkanes are typically colorless, odorless, and relatively unreactive. They form a homologous series, meaning as the number of carbon atoms increases, their boiling points, melting points, and density generally increase as well. Alkanes are mainly obtained as fossil fuels, such as petroleum and natural gas, where they exist in extensive amounts.
The general formula for alkanes is CnH2n+2, with "n" representing the number of carbon atoms. For example, methane (CH4) is the simplest alkane with one carbon atom, while ethane (C2H6), propane (C3H8), butane (C4H10), and pentane (C5H12) are examples of alkanes with increasing carbon chain lengths.
Alkanes possess relatively low reactivity due to their carbon-carbon single bonds, which are strong and difficult to break. They mainly undergo combustion reactions with oxygen, producing carbon dioxide, water, and releasing energy.
The word "alkanes" comes from the combination of two terms: "alkyl" and "ane".
The term "alkyl" derives from the German word "Alkohol", which means alcohol. It was coined by the German chemist August Wilhelm von Hofmann in 1850. "Alkyl" refers to a group of atoms derived from an alkane, by removing one hydrogen atom.
The second part of the word, "ane", comes from the Greek suffix "-ᾱνῆς" (-anes), which is commonly used to describe compounds belonging to specific classes. In the case of hydrocarbons, the suffix "-ane" signifies that a compound is an alkane.
Therefore, the word "alkanes" combines "alkyl" and "-ane" to describe hydrocarbons that belong to the class of substances derived from alcohols by removing one hydrogen atom.