-p-Block elements - I — Chemistry STD 11 Science — Question

Reason : Iodide stabilizes higher oxidation state

$ H_2(g) + Cl_2(g) \to 2HCl(g), \Delta H^o = -185\, kJ$

What is $\Delta U^o$ for this reaction? .....$kJ$

$(I)\,  1s^2\, 2s^2\, 2p^6\, 3s^2\, 3p^5$

$(II)\,  1s^2\, 2s^2\, 2p^3$

$(III)\,  1s^2\, 2s^2\, 2p^5$

$(IV)\,  1s^2\, 2s^2\, 2p^6\, 3s^2\, 3p^1$

then the solubility of $AB _{2}$ in pure water is......... $\times 10^{-4}$ $mol$ $L ^{-1}$.

[Assuming that neither kind of ion reacts with water]