Names of some organic compounds are given. Which one is not in IUPAC system?




When $$3.92 \mathrm{~g}$$ of Mohr salt is dissolved in $$100 \mathrm{~mL}$$ of water, and titrated against $$\mathrm{KMnO}_4$$ solution, $$20 \mathrm{~mL}$$ of this solution required $$18 \mathrm{~mL}$$ of $$\mathrm{KMnO}_4$$ for complete oxidation. The strength of $$\mathrm{KMnO}_4$$ is: [Molar mass of Mohr salt is $$392 \mathrm{~g} \mathrm{~mol}^{-1}$$ and $$\mathrm{KMnO}_4$$ is $$158 \mathrm{~g} \mathrm{~mol}^{-1}$$]
Among the following, which is not according to the property indicated against it?
Arrange the following in the order of increasing reactivity towards $$\mathrm{SN}_{\mathrm{2}}$$ reactions.
$$\begin{array}{ll} \left(\mathrm{CH}_3\right)_3 \mathrm{CCH}_2 \mathrm{Br}(\mathrm{P}) ; & \\\mathrm{CH}_3\left(\mathrm{CH}_2\right)_3 \mathrm{Br}(\mathrm{Q}) ; &\\ \mathrm{CH}_3 \mathrm{CH}_2-\mathrm{CH}\left(\mathrm{CH}_3\right)-\mathrm{CH}_2 \mathrm{Br}(\mathrm{R}) ; & \\\left(\mathrm{CH}_3\right)_2 \mathrm{CHCH}_2 \mathrm{CH}_2 \mathrm{Br}(\mathrm{S}) \end{array}$$