Consider the following alcohols. The order of decreasing reactivities of these alcohols towards substitution with $HBr$ is:
$(I)$ $C_6H_5CH_2OH$
$(II)$ $p-NO_2-C_6H_4CH_2OH$
$(III)$ $p-CH_3O-C_6H_4CH_2OH$
$(IV)$ $p-Br-C_6H_4CH_2OH$

The major product in the given reaction is

$A$ compound $X$ with molecular formula $C_3H_8O$ can be oxidized to a compound $Y$ with the molecular formula $C_3H_6O_2$. $X$ is most likely to be

The correct order of boiling point for primary $(1^{\circ})$,secondary $(2^{\circ})$ and tertiary $(3^{\circ})$ alcohols is

Which among the following compounds reacts fastest with $HBr$?

$A$ hydroxy compound $(X)$ with molar mass $122 \ g \ mol^{-1}$ is acetylated with acetic anhydride,using a large excess of the reagent ensuring complete acetylation of all hydroxyl groups. The product obtained has a molar mass of $290 \ g \ mol^{-1}$. The number of hydroxyl groups present in compound $(X)$ is :