Which of the following ethers is gaseous at room temperature?

The major product in the given reaction will be:
(One mole of each)
$C_6H_5O^-Na^+ + C_6H_5CH_2Cl + C_2H_5OK^+ \xrightarrow{\text{Major Product}}$

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 compounds will not yield benzoic acid upon boiling with basic $KMnO_4$ followed by acidification?

In which of the following reactions is the product an ether?

In the reaction $CH_3-CH(CH_3)-CH_2-O-CH_2-CH_3 + HI \xrightarrow{\text{Heated}} \dots$,which of the following compounds will be formed?