Aromatic Hydrocarbons — Prelims Questions

Which of the following compounds is aromatic according to Hückel's rule?

Which of the following reagents would be suitable for the nitration of benzene?

Which of the following groups is an ortho-para directing but deactivating group in electrophilic aromatic substitution?

Which of the following is a limitation of Friedel-Crafts alkylation?

What is the major product formed when toluene is treated with a strong oxidizing agent like alkaline KMnO$_4$ followed by acidification?

Which of the following compounds is NOT aromatic?