The dibromo compound $[\mathrm{P}]$ (molecular formula: $\mathrm{C}_9 \mathrm{H}_{10} \mathrm{Br}_2$ ) when heated with excess sodamide followed by treatment with dilute HCl gives [Q]. On warming [Q] with mercuric sulphate and dilute sulphuric acid yield $[R]$ which gives positive Iodoform test but negative Tollen's test. The compound $[\mathrm{P}]$ is :

Given below are two statements :

Statement I : Benzene is nitrated to give nitrobenzene, which on further treatment $$ \text { with } \mathrm{CH}_3 \mathrm{COCl} / \mathrm{AlCl}_3 \text { will give } $$

Statement II : $-\mathrm{NO}_2$ group is a $m$-directing, and deactivating group.

In the light of the above statements, choose the most appropriate answer from the options given below

80 mL of a hydrocarbon on mixing with 264 mL of oxygen in a closed U-tube undergoes complete combustion. The residual gases after cooling to 273 K occupy 224 mL . When the system is treated with KOH solution, the volume decreases to 64 mL . The formula of the hydrocarbon is :

The reactions which cannot be applied to prepare an alkene by elimination, are

Choose the correct answer from the options given below: