Which of the following substances yields benzoic acid upon oxidation?

Which of the following alkyl halides is most reactive towards the $S_{N}1$ mechanism?

The compound having the longest $C-Cl$ bond is:

Arrange the following compounds in decreasing order of the rate of electrophilic addition reaction:
$(P)$ $p$-vinylbenzaldehyde
$(Q)$ $p$-vinylanisole
$(R)$ $p$-methylstyrene
$(S)$ $p$-dimethylaminostyrene

Which of the following isomers of $C_4H_9Br$ is a chiral molecule?

Ethyl orthoformate is formed by heating which of the following compounds with sodium ethoxide?