When isobutyl magnesium bromide in dry ether is treated with absolute ethyl alcohol,the products formed are

Which compound decolorizes aqueous bromine and gives white fumes of $HCl$ on reaction with $PCl_5$?

$HC \equiv CH$ $\xrightarrow[HgSO_4]{H_2SO_4} \,\,$ $\xrightarrow[HOH]{CH_3MgBr} \,\,$ $\xrightarrow{P/Br_2} (X)$; $(X)$ is

Propene is the product obtained by the dehydrogenation of

$A$ compound is soluble in concentrated ${H_2SO_4}$. It does not decolorize a solution of bromine in ${CCl_4}$. However,it is oxidized by chromic anhydride in aqueous sulfuric acid within two seconds,changing the color of the solution from orange to blue,green,and finally opaque. What does the original compound contain?

In the following reaction sequence,$X$ and $Y$,respectively,are:
$CH_2=C(CH_3)_2$ $\xrightarrow{X} \text{Epoxide}$ $\xrightarrow{Y} (CH_3)_3C-OH$