Which of the following compounds will $NOT$ yield benzoic acid upon oxidation with alkaline $KMnO_4$ followed by heating?

In the reaction $Ar-OH + RX \xrightarrow{\text{alkali}} A$,$A$ is

The ether that undergoes electrophilic substitution reactions is

Explain the reaction of methoxyethane with concentrated $HI$ and describe its mechanism.

Which one of the following reactions will not lead to the desired ether formation in major proportion? (iso-$Bu$ $\Rightarrow$ isobutyl,sec-$Bu$ $\Rightarrow$ sec-butyl,$nPr$ $\Rightarrow$ $n$-propyl,${}^{t}Bu$ $\Rightarrow$ tert-butyl,$Et$ $\Rightarrow$ ethyl)

Which of the following will be obtained by keeping ether in contact with air for a long time?