MHTCET 18 Apr 2026 Shift 1 Paper

Concept:A chiral carbon atom is one that is bonded to four different groups.Explanation:The structure of 2-Bromo-3,4,5-trimethylhexane is:$$\mathrm{CH}_3-\mathrm{CH}(\mathrm{Br})-\mathrm{CH}(\mathrm{CH}_3)-\mathrm{CH}(\mathrm{CH}_3)-\mathrm{CH}(\mathrm{CH}_3)-\mathrm{CH}_3$$Check each carbon atom along the main chain.$\mathrm{C}_2$ is chiral because it is attached to $\mathrm{H}$, $\mathrm{Br}$, $\mathrm{CH}_3$, and the rest of the carbon chain, which are all different.$\mathrm{C}_3$ is chiral because its four groups $\mathrm{H}$, $\mathrm{CH}_3$, the $\mathrm{C}_2$ side, and the $\mathrm{C}_4$ side are different.$\mathrm{C}_4$ is chiral because the carbon chains on its two sides are different: the $\mathrm{C}_3$ side contains a bromine atom, while the $\mathrm{C}_5$ side does not.$\mathrm{C}_5$ is not chiral because it is bonded to two identical $\mathrm{CH}_3$ groups.Therefore, the molecule has exactly three chiral carbon atoms.Answer:3 chiral carbon atomsOption C.