$\mathrm{Assertion} : -$ Dehydration of alcohols always takes place in basic medium.
$\mathrm{Reason} :- {\mathrm{OH}}^{-}$ is a good leaving group

Assertion (A): $\mathrm{m}-$Nitrophenol is less acidic than $\mathrm{p}-$nitrophenol.

Reason (R): $\mathrm{p}-$Nitrophenol has intermolecular-$\mathrm{H}-$bonding.

$\mathrm{Assertion} :- \mathrm{Ph}-\mathrm{O}-{\mathrm{C}}_2{\mathrm{H}}_5$ can be prepared form $\mathrm{PhONa}$ and ethyl lodide.

$\mathrm{Reason} :-$ Aryl halides are less reactive substrates for nucleophilic substitution reaction.

$\mathrm{Assertion} :-$ Methoxy ethane has less boiling point than propanol.

$\mathrm{Reason} :-$ Methoxy ethane is more polar than propanol.