The product obtained by heating ethanol with concentrated $H_2SO_4$ at $165^{\circ}C - 170^{\circ}C$ is:

How many primary alcohol isomers are there for $C_5H_{11}OH$?

The alcohol which reacts most easily with conc. $HCl$ is

Which among the following reactions is not possible?

Why is sulphuric acid not used during the reaction of alcohols with $KI$?

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