Describe nitroso-oxime tautomerism with the help of a diagram.

For the given compound X, the total number of optically active stereoisomers is ____.

The tautomerism involving (1, 5) migration of hydrogen atom can be observed in

  

Which of the two tautomers is more stable?

The final product $\left(\mathrm{C}\right)$is :

If ${\mathrm{D}}^{+}$ is catalyst. What is the compound $\mathrm{A}$?

Represent the union of two sets by Venn diagram for each of the following.

$X=\{x | x$ is a prime number between $80$ and $100\}$

$Y=\{y | y$ is an odd number between $90$ and $100\}$