Which of the following reagents will convert glycerol into acrolein?

In the following reactions:
$1.$ Compound $X$ is
$2.$ The major compound $Y$ is
Give the answer for question $1$ and $2.$

The order of reactivity of $C_2H_6$,$C_2H_4$,and $C_2H_2$ is.......

Product $(A)$ is

Which one of the following characteristics applies to both ethene and ethyne?

Identify the product $B$ in the following reaction sequence:
$1,4-\text{cyclohexadiene-1,4-dicarboxylic acid}$ $\xrightarrow{NaOH} A$ $\xrightarrow{\text{Kolbe electrolysis}} B$