Question

What does the prefix n- mean in orgo nomenclature?

Answer 1

Hint: Nomenclature is basically a process in which names are given to the non-living and living substances. For this purpose, various suffixes and prefixes are used to make this easier. For example- for alkane suffix- ane is used and if $$1$$ carbon is present then prefix- meth is used.

Complete answer:
Here, we need to explain the need of the prefix in the nomenclature. So, for that let’s study about prefix and suffix first. For the nomenclature, IUPAC nomenclature is also used for naming organic and inorganic compounds. This system standardised the names of the compounds all over the world.

In IUPAC nomenclature, suffix is used for the functional groups present in the compound. Suffixes are written at the end of the nomenclature. For example: suffix for alkanes, alkenes, carboxylic acids, aldehyde, esters are –ane, -ene, -oic acid, -al, -oate.

And prefix is used for the substituent groups, side chains, present in the compound. Prefixes are written at the start of the compound. It also helps us to know whether the compound is cyclic or acyclic just by looking at the nomenclature of the compound. For example; is two carbons are present then we use prefix as Eth- and if three carbons are present then we use prefix as Prop- and so on.

Therefore, the prefix – n is used for a straight chain which means that there is no branching in the compound; only a straight chain is present. Let’s see an example for this:
$C{H}_3-C{H}_2-C{H}_2-C{H}_2-C{H}_3$
Here five carbons are present in the straight chain, there is no branching present in this compound.

Since, there are five carbons and no double or triple bond is there so its name is pentane and no branching is there, it’s a straight chain so we will use prefix – n.

Therefore we can conclude in general that the prefix "n-" (or normal) is used when all carbons form a continuous, unbranched (linear) chain. If a functional group (such as an alcohol) is present that functional group is on the end of the chain.

Prefix – n is used for straight chain only.

Note: Nomenclature of the compounds gives us a lot of information just by looking at the name of the compound and for that we need to know all these prefixes and suffixes. We can easily elucidate the structure with the help of this system and also it is a standard system, that is, it is used all over the world. So, if the nomenclature of the compound is n – pentane, then it is known as n – pentane only all over the world.