Williamson's synthesis is used to prepare

Ethers are prepared from alcohols by Williamson synthesis. Heating ethanol with sulfuric acid at $413 \ K$ gives ethoxyethane. Match the ether compounds in Column-$I$ with the products formed upon heating with $HI$ in Column-$II$.

Column-$I$ (Ether)	Column-$II$ (Product)
$(A)$ $CH_3CH_2-CH(CH_3)-CH_2-OCH_2CH_3$	$(i)$ $CH_3OH + CH_3-C(CH_3)_2-I$
$(B)$ $CH_3CH_2CH_2-O-C(CH_3)_2CH_2CH_3$	(ii) $C_6H_5OH + C_6H_5CH_2I$
$(C)$ $C_6H_5CH_2-O-C_6H_5$	(iii) $CH_3CH_2CH_2OH + CH_3CH_2-C(CH_3)_2-I$
$(D)$ $CH_3-C(CH_3)_2-O-CH_3$	(iv) $CH_3CH_2-CH(CH_3)-CH_2OH + CH_3CH_2I$

Write the mechanism of the reaction of $HI$ with methoxybenzene.

An organic compound with the molecular formula $C_3H_6O$ does not give a precipitate with $2,4-$dinitrophenylhydrazine $(2,4-DNP)$ and does not react with sodium metal. What is this compound?

Identify the missing reagent in the following reaction: $C_6H_5OCH_3 + (?) \rightarrow \text{p-methoxyacetophenone (major)} + \text{o-methoxyacetophenone (minor)}$

When ethyl bromide is treated with dry $Ag_2O$,the main product is: