Answer
The IUPAC names of the compounds are:
(a) The three isomers of $C_{5}$$H_{12}$ -
(i) pentane
(ii) 2-Methylbutane
(iii) 2,2-Dimethylpropane
(b) 2,3-Dimethylpentane
(c) 2,4-Dimethylpentane
(d) 2,2,5-Trimethylhexane
Work Step by Step
Steps to write the IUPAC names of the compounds
1. Identify the longest carbon chain and number it. The number of carbon atoms in this chain gives the word root.
2. In case of Side-chains/substituents, assign them the numbers (called locants) to indicate the point of attachment to the parent hydrocarbon chain. These substituents are written as the prefix to the word root, preceded by the locant (position in the hydrocarbon chain).
3. When two different substituents are present, state them in alphabetical order.
4. If there are two substituents on the same carbon, they are assigned the same number.
5. Since the compounds are saturated, they are given the suffix -ane.