Question

Enthalpy of a reaction at ${27}^{\circ }C$ is $15kJmo{l}^{-1}$ The reaction will be feasible if entropy is

• A. $15Jmo{l}^{-1}{K}^{-1}$
• B. $50Jmo{l}^{-1}{K}^{-1}$
• C. greater than $50Jmo{l}^{-1}{K}^{-1}$
• D. less than $50Jmo{l}^{-1}{K}^{-1}$

Answer 1

The correct option is C greater than $50Jmo{l}^{-1}{K}^{-1}$

We know,
$△G=△H-T△S$
for a reaction to be feasible it should be sponteneous, that is when,
$△G=-ve$
and for that $T△S$ should be greater in magnitutde than $△H$ i.e.
$\Rightarrow T△S>△HT=27+273=300K\Rightarrow 300△S>15000Jmo{l}^{-1}\Rightarrow △S>50Jmo{l}^{-1}{K}^{-1}$