Ethyl alcohol on oxidation with $K_2Cr_2O_7$ gives

What is the product obtained when isopropyl alcohol vapor is passed over heated copper?

Arrange the following compounds in decreasing order of their boiling point $(BP)$:
$CH_3CHO$ $(I)$,$CH_3CH_2OH$ $(II)$
$CH_3OCH_3$ $(III)$,$CH_3CH_2CH_3$ $(IV)$

$CH_3 CH_2 OH$ $\xrightarrow{Cl_2} CH_3 CHO$ $\xrightarrow{3 Cl_2} Cl_3 CCHO$. In the above reactions,the role of $Cl_2$ in step-$1$ and step-$2$ respectively is:

The major product formed in the following reaction: $CH_3CH(Cl)CH_2CH_2OH \xrightarrow{Aq. KOH}$ is

The major product of the following reaction is: