Identify the products $[A]$ and $[B]$,respectively in the following reaction:

Phenol $(C_6H_6O)$ $\xrightarrow{Br_2 \text{ in } CS_2}$ $X$ (Major product)
Phenol $(C_6H_6O)$ $\xrightarrow{Br_2 \text{ in } H_2O}$ $Y$ (Major product)
What are $X$ and $Y$ in the above reaction respectively?

The reaction is given as: $X \xrightarrow{Y} \text{Benzoquinone}$. Identify $X$ and $Y$ in the above reaction.

The structure of the compound that gives a tribromo derivative on treatment with bromine water is

Which of the following processes does not give benzene as a product?

$A$ trisubstituted compound '$A$',$C_{10}H_{12}O_2$ gives a neutral $FeCl_3$ test positive. Treatment of compound '$A$' with $NaOH$ and $CH_3Br$ gives $C_{11}H_{14}O_2$,with hydroiodic acid $(HI)$ gives methyl iodide,and with hot conc. $NaOH$ gives a compound $B$,$C_{10}H_{12}O_2$. Compound '$A$' also decolorises alkaline $KMnO_4$. The number of $\pi$ bonds present in the compound '$A$' is $...........$