Ethylene may be obtained by dehydration of which of the following with concentrated $H_2SO_4$ at $160 - 170\,^{\circ}C$?

Which of the following gives immediate turbidity on reaction with Lucas reagent $(HCl/ZnCl_2)$?

The conversion of $2-$methylpropan$-1-$ol to $2-$methylpropan$-2-$ol is:

The given reaction is known as :

An optically active alcohol of formula $C_9H_{12}O_2$ produced the following compound when refluxed with $KMnO_4$. What is the structure of $(A)$? The original compound showed these properties also:
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow{Na} H_2 \text{ liberated}$
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow{Br_2} \text{ no rapid reaction}$
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow[{cool}]{CrO_3 / H^{+}} C_9H_8O_3$

To remove last traces of water from alcohol,the metal used is