Short Answer Type

Elimination reactions (especially $\mathrm{\beta }-$elimination) are as common as the nucleophilic substitution reaction in case of alkyl halides. Specify the reagents used in both cases.

How will you obtain monobromobenzene from aniline?

Aryl halides are extremely less reactive towards nucleophilic substitution. Predict and explain the order of reactivity of the following compounds towards nucleophilic substitution:

tert-Butyl bromide reacts with aq. $\mathrm{NaOH}$ by ${\mathrm{S}}_{\mathrm{N}}1$ mechanism while $\mathrm{n}-$butyl bromide reacts by ${\mathrm{S}}_{\mathrm{N}}2$ mechanism. Why?

Predict the major product formed when $\mathrm{HCl}$ is added to isobutylene. Explain the mechanism involved.

Discuss the nature of $\mathrm{C}–\mathrm{X}$ bond in the haloarenes.

How can you obtain iodoethane from ethanol when no other iodine containing reagent except $\mathrm{NaI}$ is available in the laboratory? 

Cyanide ion acts as an ambident nucleophile. From which end it acts as a stronger nucleophile in aqueous medium? Give reason for your answer.