Acetic acid will be obtained on oxidation of

Identify the product formed in the following reaction.
$CH_3CH_2MgBr \xrightarrow[\text{ii) dil. } HCl]{\text{i) Dry ice / dry ether}} \text{Product}$

Which of the following is a laboratory method for the preparation of acetyl chloride?

Which of the following processes can be used to oxidize toluene to benzoic acid?

Find product $V$ in the following reaction sequence:
$CH_3-CH(CH_3)-COOH$ $\xrightarrow[H_3O^{+}]{LiAlH_4} I$ $\xrightarrow{PBr_3} II$ $\xrightarrow[ether]{Mg} III$ $\xrightarrow{CO_2} IV$ $\xrightarrow{H_3O^{+}} V$

Which of the following reaction sequences converts $R-CH_2CH_2OH$ into $R-CH_2CH_2COOH$?