Compound (Y) gives iodoform test, that means it contains acetyl group (CH3−
O
||
C
−). PCC is an oxidising agent which oxidised the alcohol to aldchyde or ketone (depends upon the reactant alcohol). That means X is an alcohol. From the given information, it is concluded that the compound X is an alcohol (which contain two carbon). Thus, the alcohol is CH3CH2OH. The reaction involves arc as follows :