Correct statements from the following are

A. Potassium dichromate is an oxidising agent and it oxidises $\mathrm{FeSO}_4$ to $\mathrm{Fe}_2\left(\mathrm{SO}_4\right)_3$ in acidic medium.

B. Sodium dichromate can be used as primary standard in volumetric estimation.

C. $\mathrm{CrO}_4^{2-}$ and $\mathrm{Cr}_2 \mathrm{O}_7^{2-}$ are interconvertible in aqueous solution by varying the pH of the solution.

D. $\mathrm{Cr}-\mathrm{O}-\mathrm{Cr}$ bond angle in $\mathrm{Cr}_2 \mathrm{O}_7^{2-}$ is $126^{\circ}$.

Choose the correct answer from the options given below :

$$ \text { Match the LIST-I with LIST-II } $$

Choose the correct answer from the options given below :

Increasing order of electron withdrawing power of following functional groups is :

a. -CN

b. -COOH

c. $-\mathrm{NO}_2$

d. -I

$$ \text { An alkene }(\mathrm{X}) \text { on ozonolysis followed by reduction gives following products. } $$

$$ \text { The alkene }(\mathrm{X}) \text { is : } $$