The major product obtained from the reaction of $2$-bromopentane with potassium ethoxide in ethanol is ....................

The reaction for the preparation of ethene from ethyl chloride is known as......

The rate of $S_N2$ reaction will be negligible in:

Explain the mechanism of a unimolecular nucleophilic substitution $(S_N1)$ reaction with a suitable example.

Two isomers $(A)$ and $(B)$ with molar mass $184 \ g/mol$ and elemental composition $C, 52.2 \ \%; H, 4.9 \ \%$ and $Br, 42.9 \ \%$ give benzoic acid and $p$-bromobenzoic acid,respectively,on oxidation with $KMnO_4$. Isomer '$A$' is optically active and gives a pale yellow precipitate when warmed with alcoholic $AgNO_3$. Isomer '$A$' and '$B$' are,respectively .... .

Non-occurrence of the following reaction
$Br^{-} + CH_3OH \rightarrow BrCH_3 + OH^{-}$,is due to