Glycerine has:

Identify $Z$ in the series:
$CH_2 = CH_2$ $\xrightarrow{HBr} X$ $\xrightarrow[Hydrolysis, Na_2CO_3]{I_2 (excess)} Z$

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:
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow{Na} H_2 \text{ liberated}$
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow{Br_2} \text{ no rapid reaction}$
$\mathop {C_9H_{12}O_2}\limits_{(A)} \xrightarrow[{cool}]{CrO_3 / H^{+}} C_9H_8O_3$

The final product $(III)$ is

What is the product $A$ in the following reaction?
$2-(but-3-en-1-yl)oxirane \xrightarrow{H_3O^{+}} A$

Ethyl hydrogen sulphate is obtained by the reaction of $H_2SO_4$ on