The number of sigma $(\sigma)$ bonds and pi $(\pi)$ bonds in benzene are respectively .......

The correct order of the rate of $EAS$ (electrophilic aromatic substitution) for the given compounds is:

The major product $X$ is:

In the given reaction: $CH_3COCH_3 \xrightarrow{\text{Conc. } H_2SO_4, \text{Distillation}} [X]$. $[X]$ will be:

Benzene vapour mixed with air when passed over $V_2O_5$ catalyst at $775 \ K$ gives

For the following Friedel-Crafts alkylation reaction,which of the statements are correct?
$A$. Major product is n-propyl benzene.
$B$. iso-propyl carbocation intermediate is also generated.
$C$. Multiple substitution is inevitable.
$D$. Introducing electron-donating substituent on benzene will not produce any alkyl benzene.