When trans$-2-$butene reacts with ${\mathrm{Br}}_2/{\mathrm{CCl}}_4,\mathrm{X}$ number of products are formed. Whereas when trans$-2-$butene reacts with $\mathrm{HBr}$, $\mathrm{Y}$ number of products are formed. Report your answer as $\mathrm{XY}$.

$\mathrm{R}-2-$ chloropentane $\underset{{\mathrm{Cl}}_2}{\overset{\mathrm{hv}}{\to }}$ Monochlorination takes place.

The total number of monochlorinated products formed in the above reaction is $\mathrm{x}$. Find the value of $\mathrm{x}$

Find the number of carbons present in the compound $\text{'}\mathrm{C}\text{'}$ formed in the following series of reactions:

${\mathrm{CH}}_3-\mathrm{Br}\stackrel{ \mathrm{KCN} }{\to }\mathrm{A}\stackrel{{\mathrm{H}}_3{\mathrm{O}}^{+}}{\to }\mathrm{B}$ $\frac{{\mathrm{LiAlH}}_4,\mathrm{ether}}{{\mathrm{H}}^{+},{\mathrm{H}}_2\mathrm{O}} \mathrm{C}$ 

In ${\mathrm{S}}_{\mathrm{N}}1$ reaction, the racemisation takes place. It is due to:

Rank the following compounds in the order of increasing ${\mathrm{E}}_2$ reaction rate with alcoholic $\mathrm{KOH}$.

$50\%$ of the reagent is used for dehydrohalogenation of $6.45 \mathrm{g} {\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{Cl}$. What will be the weight of the main product obtained?
[Atomic mass of $\mathrm{H}, \mathrm{C}$ and $\mathrm{Cl}$ are $1, 12$ and $35.5 \mathrm{g}/\mathrm{mole}$, respectively].