Which product is obtained by the oxidation of ethylbenzene with $KMnO_4$?

Benzene does not undergo addition reactions easily because ...............

Which of the following statements regarding Friedel-Crafts alkylation is incorrect?

The enthalpy of hydrogenation of cyclohexene is $-119.5 \ kJ \ mol^{-1}.$ If resonance energy of benzene is $-150.4 \ kJ \ mol^{-1},$ its enthalpy of hydrogenation would be $...... \ kJ \ mol^{-1}.$

Styrene at room temperature is

Amongst the following compounds,the one which is most easily sulphonated is: