The most appropriate reagent to distinguish between acetaldehyde and formaldehyde is

Which of the following statements regarding the chemical properties of acetophenone is incorrect?
$I.$ It is reduced to methyl phenyl carbinol by sodium and ethanol.
$II.$ It is oxidized to benzoic acid with acidic $KMnO_4$.
$III.$ It does not undergo electrophilic substitution reactions (like nitration at the $m$-position).
$IV.$ It does not give the iodoform test with iodine and alkali.

An organic compound $B$ is formed by the reaction of ethylmagnesium iodide $(CH_3CH_2MgI)$ with a substance $A,$ followed by treatment with dilute aqueous acid. Compound $B$ does not react with $PCC$ in dichloromethane. Identify $A$.

Aldehydes and ketones can be reduced to hydrocarbons by using:

The following transformation can be best carried out using:

The product formed in the given reaction sequence is: