JEE Advanced 2020 — Paper 2 — Question 32

Tin is obtained from cassiterite by reduction with coke. Use the data given below to determine the minimum

temperature (in K ) at which the reduction of cassiterite by coke would take place.

At $298 \mathrm{~K} ; \Delta_{f} H^{0}\left(\mathrm{SnO}_{2}(\mathrm{~s})\right)=-581.0 \mathrm{~kJ} \mathrm{~mol}^{-1}, \Delta_{f} H^{0}\left(\mathrm{CO}_{2}(g)\right)=-394.0 \mathrm{~kJ} \mathrm{~mol}^{-1}$,

$S^{0}\left(\mathrm{SnO}_{2}(s)\right)=56.0 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}, S^{0}(\mathrm{Sn}(\mathrm{s}))=52.0 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$,

$S^{0}(\mathrm{C}(s))=6.0 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}, S^{0}\left(\mathrm{CO}_{2}(\mathrm{~g})\right)=210.0 \mathrm{~J} \mathrm{~K}^{-1} \mathrm{~mol}^{-1}$,

Assume that the enthalpies and the entropies are temperature independent.