Question

Following alkanes are wrongly named. Write their correct IUPAC names.
1.2-Ethylbutane
2.4-Methylpentane
3.3,5-Dimethylhexane
4.5-Ethyl-4-methylheptane
5.2,3-Dimethyl-3-ethlypentane
6.3-Methyl-4-isopropylheptane
7.4-Ethyl-5-sec-nutylnonane

Answer 1

Before naming the compound, we should first know about the IUPAC. The concept of IUPAC was introduced so that there is a standardized manner to name the compound all over the world and it will be the same. The motive was to give identity to every compound and a unique name.

Complete answer:
Rule for the IUPAC Nomenclature-
We have to find the parent hydrocarbon chain: It should have the maximum number of branches, substituents, length, number of multiple bonds, or single bonds.
We have to identify the parent functional group, we should know which group holds the highest priority.
Then identify the side chains that are branched from the parent chain.
Identify the functional groups that are left and see the positions they are attached to. Write those numbers as the prefix while naming.
Identify the bonds (double/triple)
Then, we have to do the numbering of the chain in the order of priority.
If a type of substituent is present more than once, then we add a prefix like di for 2, tri for 3, tetra for 4, etc.
2-Ethylbutane $\to$ 2-ethyl-butane
4-Methylpentane$\to$ 4-methyl-pentane
3,5-Dimethylhexane$\to$3,5-dimethyl-hexane
5-Ethyl-4-methylheptane$\to$5-ethyl-4-methyl-heptane
2,3-Dimethyl-3-ethlypentane$\to$3-ethyl-2,3-dimethyl-pentane
3-Methyl-4-isopropylheptane$\to$4-isopropyl-3-methyl-heptane
4-Ethyl-5-sec-nutylnonane$\to$5-sec-butyl-4-ethyl-nonane

Note:
Different IUPAC Methods are:
Compositional Nomenclature- The nomenclature involves naming based on the composition of the substance.
Substitutive Nomenclature- The nomenclature involves naming based on the composition of the substance.
Additive Nomenclature- The nomenclature is used to name the coordination compounds.