3. Classification of elements and periodicity in properties — Chemistry STD 11 Science — Question

$MgO(s) + C(s) \to Mg(s) + CO(g)$, for which $\Delta _r{H^o} =  + 491.1\,kJ\,mo{l^{ - 1}}$ and $\Delta _r{S^o} =  198.0\,Jk^{-1}\,mo{l^{ - 1}}$ is not feasible at $298\, K$. Temperature above which reaction will be feasible is.....$K$

$S\left( s \right) + {O_2}\left( g \right) \rightleftharpoons S{O_2}\left( g \right);{K_1} = {10^{52}}$

$2S\left( s \right) + 3{O_2}\left( g \right) \rightleftharpoons 2S{O_3}\left( g \right);{K_2} = {10^{129}}$

The equilibrium constant for the reaction $2S{O_2}\left( g \right) + {O_2}\left( g \right) \rightleftharpoons 2S{O_3}\left( g \right)$ is