Which order is correct for the decreasing reactivity toward ring monobromination of the following compounds:
$I. \, C_6H_5CH_3$
$II. \, C_6H_5COOH$
$III. \, C_6H_6$
$IV. \, C_6H_5NO_2$

On heating a mixture of sodium benzoate and sodalime,the following is obtained:

Consider the following sequence of reactions. In $Z$,the number of $sp^3$ carbons is $a$ and $sp^2$ carbons is $b$. The value of $(a+b)$ is:
$CH_3CH_2CH_2CH_2Br$ $\xrightarrow[\text{dry ether}]{Na} X$ $\xrightarrow[\text{10-20 atm}]{\text{Cr}_2\text{O}_3 / 773 \text{ K}} Y$ $\xrightarrow[\text{anhy. AlCl}_3]{\text{CH}_3\text{COCl}} Z$

Which of the following reacts with benzene in the presence of anhydrous aluminum chloride to form acetophenone?

Toluene on oxidation with dilute $HNO_3$ and alkaline $KMnO_4$ gives:

What is the major product $X$ in the following reaction?
$\text{Benzene} + CH_3CH_2CH_2Cl \xrightarrow{AlCl_3} (X)$