$n$-Propyl alcohol and isopropyl alcohol can be chemically distinguished by which of the following reagents?

Explain the mechanism of dehydration of alcohols with a suitable example.

Given below are two statements :
Statement $I$ :
In Lucas test,primary,secondary and tertiary alcohols are distinguished on the basis of their reactivity with conc. $HCl + ZnCl_{2}$,known as Lucas Reagent.
Statement $II$ :
Primary alcohols are most reactive and immediately produce turbidity at room temperature on reaction with Lucas Reagent.
In the light of the above statements,choose the most appropriate answer from the options given below :

An aromatic compound $A$ of the molecular formula $C_8H_{10}O$ on reaction with iodine and dilute $NaOH$ gives a yellow precipitate. The structure of the compound is expected to be

$A$ 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 :

Which compound is soluble in water?