$$ \text {Identify }[\mathrm{A}],[\mathrm{B}] \text { and }[\mathrm{C}] \text {, respectively in the following reaction sequence : } $$

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

LIST-I (Molecules/ion)		LIST-II (Hybridisation of central atom)
A.	$$ \mathrm{PF}_5 $$	I	$$ \mathrm{dsp}^2 $$
B	$$ \mathrm{SF}_6 $$	II	$$ \mathrm{sp}^3 \mathrm{~d} $$
C	$$ \mathrm{Ni}(\mathrm{CO})_4 $$	III	$$ \mathrm{sp}^3 \mathrm{~d}^2 $$
D	$$ \left[\mathrm{PtCl}_4\right]^{2-} $$	IV	$$ \mathrm{sp}^3 $$

$$ \text { Choose the correct answer from the options given below: } $$

Which of the following postulate of Bohr's model of hydrogen atom is not in agreement with quantum mechanical model of an atom?

In the following system, $\mathrm{PCl}_5(\mathrm{~g}) \leftrightharpoons \mathrm{PCl}_3(\mathrm{~g})+\mathrm{Cl}_2(\mathrm{~g})$ at equilibrium, upon addition of xenon gas at constant T \& p , the concentration of