$A$ mixture of $C_2H_6, C_2H_4$ and $C_2H_2$ is bubbled through an alkaline solution of copper$(I)$ chloride,contained in a Woulf's bottle. The gas coming out is

What sequence of reagents is required to accomplish the following transformation?

The cycloalkane $(X)$ on bromination consumes one mole of bromine per mole of $(X)$ and gives product $(Y)$ in which $C:Br$ ratio is $3:1$. The percentage of bromine in the product $(Y)$ is $ . . . . . . \%$ (Nearest integer).
(Given: Molar mass in $g \ mol^{-1}$, $H:1, C:12, O:16, Br:80$)

The product of the reaction shown below will be:

Which of the following is a major product of the reaction shown below?

Which of the following reactions results in the formation of a pair of diastereomers?