Dehydration of Alcohols

$$\begin{aligned}\text{R--CH}_2\text{--CH}_2\text{OH} \xrightarrow{\text{Conc. H}_2\text{SO}_4, \, 170^\circ\text{C}} \text{R--CH=CH}_2 + \text{H}_2\text{O}\end{aligned}$$

Ease of Dehydration: $$ 3^\circ > 2^\circ > 1^\circ$$ (Involves carbocation intermediate; hydride/methyl shifts occur)