Which of the following does not contain an acyl group?

The value of $n$ in the given reaction is:

Ethanol when reacts with $PCl_5$ gives $A$,$POCl_3$ and $HCl$. $A$ reacts with dry $Ag_2O$ to form $B$ (major product) and $AgCl$. $A$ and $B$ respectively are

Chloroethane reacts with $X$ to form diethyl ether. What is $X$?

The product of the reaction between $2-$methyltetrahydrofuran and $HI$ is:

Which of the following reactions will not yield an alkyl halide?