Alkanes- Nomenclature

Introduction

Many compounds with the same structural formula were referred to by a variety of different names depending on where they were synthesized. As it caused so much confusion, this naming scheme was laughable. Finally, the IUPAC (International Union for Pure and Applied Chemistry) established a standard naming system for chemical compounds that included a set of standard rules. IUPAC nomenclature or IUPAC naming is the name given to this method of naming. Nomenclature, or how things are named, is one of the main differences between chemistry and natural language. Second, written language is more important than spoken language. There are numerous nomenclatures in chemistry, including those for elements, compounds, reactions, apparatus, and theoretical concepts.

IUPAC Nomenclature of Alkanes

IUPAC nomenclature or IUPAC naming is the name given to this method of naming. Following is an explanation of the IUPAC nomenclature for alkanes, alkynes, and alkenes: In our knowledge of hydrocarbons, alkanes are the simplest. C_nH_(2n+2) is the general formula for these compounds. Carbon and hydrogen are only linked together by a single carbon-to-hydrogen bond in alkanes. This series of organic compounds, known as a “homologous series,” is made up of compounds that share a functional group but differ from one another by a “–CH₂” group. In contrast, unsaturated hydrocarbons such as alkenes and alkynes exist. There is a double bond linkage in alkenes and a triple bond linkage in alkynes, respectively. Alkanes, alkenes and alkynes are referred to as such in the IUPAC nomenclature below: In the case of alkanes, the parent chain is the one with the longest hydrocarbon chain. With regard to alkenes and alkynes, the parent chain is typically the hydrocarbon chain that has two or three double or triple bonds. The Greek alphabet is used to name the parent chain, such as hepta, octa, and so on. If you’re talking about alkanes, you use the suffix “-ane,” if you want to refer to alkenes, you use “-ene,” and for alkynes, you use “yne.” A few examples: Ethane, C₂H₄, and Ethyne are all names for C₂H₂. Carbon atoms that are double- or triple-bonded are numbered first in the parent chain. Numbers are used to indicate the location of the carbon atom with the double bond. As an example, Pent-2-ene, CH₃CH=CHCH₂CH₃, is referred to as such. Greek numerical prefixes such as di, tri are used to denote the number of double bonds in the carbon chain when there are more than one.

Nomenclature of Halogenated alkanes

There are two ways of naming halogenated alkanes. The alkyl group is named first in the common system, followed by a suitable word chloride, bromide, etc. Two separate words are always used when referring to an alkyl halide. Alkyl halides are known as haloalkanes in the IUPAC nomenclature. In addition to these, the following guidelines govern the designation of compounds:

• Identify the halogen-containing carbon chain that is the longest
• Number the chain so that the carbon atom carrying the halogen atom has the smallest possible number
• If the carbon chain contains two or three double or triple bonds, this is given precedence when determining the number of carbon atoms
• Halogen derivatives’ IUPAC names are always just one word

Alkane as saturated hydrocarbons

Covalent bonds between carbon and hydrogen atoms are present in alkanes. Saturated hydrocarbons are the term for these compounds. Carbon and hydrogen atoms with one covalent bond make up this class of compounds. A homologous series with the molecular formula C_nH_(2n+2) is also included. A family of hydrocarbons known as alkanes is the simplest one. Carbon and hydrogen are the only elements in them. There are four bonds formed between carbon atoms, and one bond is formed between hydrogen atoms. Since condensed structural formulas are more difficult to draw, chemists prefer using line-angle formulas. An additional condensed form of alkane i.e., structural formulas is possible. In the case of methane, which is a simple alkane, there is only one carbon atom and the molecular formula CH₄. A single covalent bond connects each additional carbon atom in a long chain alkane molecule. A total of four single covalent bonds are formed between each atom and the hydrogen atoms it is attached to. octane is the chemical structure name for this long-chain hydrocarbon molecule. C8H18 is the molecular formula for an eight-carbon alkane.

Physical Properties of Alkanes

1. In Alkanes, the Solubility.

Since the C-C bond or C-H bond is covalent, alkanes are nonpolar molecules. In general, we find polar molecules dissolve in polar solvents, and nonpolar molecules dissolve in nonpolar solvents. Therefore, alkanes are hydrophobic, or water-insoluble. Inorganic solvents can dissolve Van der Waals forces because the energy required to overcome them and generate new Van der Waals forces is so similar.

2. The Alkane Boiling Point.

There are more Van der Waals forces between molecules as their size or surface area increases. Boiling point increases with increasing molecular weight for straight-chain alkanes compared to their structurally identical isomers, as shown in the graph.

3. Temperature at which Alkanes Melt.

Because of their increasing molecular weight, alkanes have the same melting and boiling points. Because higher alkanes are solids, the intermolecular forces of attraction between them are extremely difficult to break. Due to their compact structure in the solid phase, even-numbered alkanes have a higher melting point than their odd-numbered counterparts.

Conclusion

All alkanes have the suffix -ane at the end of their names. No matter whether or not the carbons in the chain are linked together end to end or contain side chains and branches, the name of every carbon-hydrogen chain that does not have double bonds or functional groups will end with ane. In the case of carbon chains that are unbranched, the number of carbons in the chain is used to identify alkanes.