9. Hydricarbon — Chemistry STD 11 Science — Question

Statement $I$: Nitration of benzene involves the following step -

(Image)

Statement $II$: Use of Lewis base promotes the electrophilic substitution of benzene.

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

$(i)\, 6C(s) + 3H_2(g) \to C_6H_6(l) ; \Delta H = +45.9\,kJ$

$(ii)\, H_2(g) +\frac {1}{2}O_2(g) \to H_2O(l) ; \Delta H = -285.9\,kJ$

$(iii) \,C(s) + O_2(g) \to CO_2(g) ; \Delta H = -393.5\,kJ$

.....$kJ$

$\mathrm{Cd}_{(s)}+\mathrm{Hg}_{2} \mathrm{SO}_{4(s)}+\frac{9}{5} \mathrm{H}_{2} \mathrm{O}_{(l)} \rightleftharpoons \mathrm{CdSO}_{4} \cdot \frac{9}{5} \mathrm{H}_{2} \mathrm{O}_{(s)}+2 \mathrm{Hg}_{(l)}$

The value of $\mathrm{E}_{\text {cell }}^{0}$ is $4.315\, \mathrm{~V}$ at $25^{\circ} \mathrm{C}$. If $\Delta \mathrm{H}^{\circ}=-825.2\, \mathrm{~kJ} \,\mathrm{~mol}^{-1}$, the standard entropy change $\Delta \mathrm{S}^{\circ}$ in $\mathrm{J} \,\mathrm{K}^{-1}$ is ........ . (Nearest integer) [Given : Faraday constant $=96487\, \mathrm{C}\, \mathrm{mol}^{-1}$ ]