Standard entropies of $\mathrm{X}_2, \mathrm{Y}_2$ and $\mathrm{XY}_5$ are 70,50 and $110 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$ respectively. The temperature in Kelvin at which the reaction
$\frac{1}{2} \mathrm{X}_2+\frac{5}{2} \mathrm{Y}_2 \rightleftharpoons \mathrm{XY}_5 \Delta \mathrm{H}^{\Theta}=-35 \mathrm{~kJ} \mathrm{~mol}^{-1}$
will be at equilibrium is_______. (Nearest integer)

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Aicharya · Accepted Answer

$\begin{aligned} & \frac{1}{2} \mathrm{X}_2+\frac{5}{2} \mathrm{Y}_2 ightleftharpoons \mathrm{XY}_5 \ & \Delta \mathrm{~S}_{\mathrm{Rxn}}^0=110-\left[\left(\frac{1}{2} 	imes 70ight)+\left(\frac{5}{2} 	imes 50ight)ight] \ & =110-160=-50 \mathrm{JK}^{-1} \mathrm{~mol}^{-1} \ & \Delta \mathrm{G}^0=0 	ext { at eqb } \ & \Delta \mathrm{G}^0=\Delta \mathrm{H}^0-\mathrm{T} \Delta \mathrm{S}^0 \ & 0=-35000-\mathrm{T}(-50) \ & \mathrm{T}=700 \mathrm{Kelvin}\end{aligned}$

Standard entropies of $\mathrm{X}_2, \mathrm{Y}_2$ and $\mathrm{XY}_5$ are 70,50 and $110 \mathrm{~J}…

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