The dihedral angle in staggered form of Newmann's projection of$1,1,1$-Trichloro ethane is $\dots \dots \dots$degree. (Round off the answer to the nearest integer)

Presence of which reagent will affect the reversibility of the following reaction, and change it to a irreversible reaction :

$\mathrm{C}{\mathrm{H}}_4+{\mathrm{I}}_2\underset{\mathrm{Reversible}}{\overset{\mathrm{hv}}{\rightleftharpoons }}{\mathrm{CH}}_3-\mathrm{I} + \mathrm{HI}$

Which one of the following is the major product of the given reaction?

In the following sequence of reactions, the final product $\mathrm{D}$ is:

For the given reaction:

What is $\mathrm{A}$?

The major product formed in the following reaction is:

Consider the above chemical reaction. The total number of stereoisomers possible for Product "P" is _________