But-2-yne and hydrogen (one mole each) are separately treated with (i) $\mathrm{Pd} / \mathrm{C}$ and (ii) $\mathrm{Na} /$ liq. $\mathrm{NH}_3$ to give the products X and Y respectively.

Identify the incorrect statements.

A. X and Y are stereoisomers.

B. Dipole moment of $X$ is zero.

C. Boiling point of X is higher than Y .

D. X and Y react with $\mathrm{O}_3 / \mathrm{Zn}+\mathrm{H}_2 \mathrm{O}$ to give different products.

Choose the correct answer from the options given below :

Given below are two statements :

Statement I : $\left[\mathrm{CoBr}_4\right]^{2-}$ ion will absorb light of lower energy than $\left[\mathrm{CoCl}_4\right]^{2-}$ ion.

Statement II : In $\left[\mathrm{CoI}_4\right]^{2-}$ ion, the energy separation between the two set of d-orbitals is more than $\left[\mathrm{CoCl}_4\right]^{2-}$ ion.

In the light of the above statements, choose the correct answer from the options given below :

Which of the following statements regarding the energy of the stationary state is true in the following one - electron systems ?

The crystal field splitting energy of $\left[\mathrm{Co}(\text { oxalate })_3\right]^{3-}$ complex is ' $n^{\prime}$ times that of the $\left[\mathrm{Cr}(\text { oxalate })_3\right]^{3-}$ complex. Here ' $n$ ' is $\_\_\_\_$ . (Assume $\Delta_0 \gg P$ )