What is the product formed when ethylbenzene is oxidized by $KMnO_4$?

Write a detailed note on the structure of benzene.

Which of the following molecules is not aromatic?

Identify the compound $(X)$ in the following reaction:
[Image of $1,3$-dinitrobenzene reacting with $HNO_3 + H_2SO_4$ to form $(X)$]
Compound $(X)$ is:

Friedel-Crafts acylation reaction can be used to obtain the compounds:

Consider the following compounds/species:
The number of compounds/species which obey $H$ückel's rule is $..........$