Browse Questions
Thermodynamics

# A reaction is non-spontaneous at the freezing point of water but is spontaneous at the boiling point of water, then

 $\Delta H$ $\Delta S$ A + Ve + Ve B - Ve - Ve C - Ve + Ve D + Ve - Ve

Can you answer this question?

For spontaneity; $\Delta G = -ve$
$\Delta G = \Delta H - T\Delta S$
$\Delta H$, for endothermic process is +ve
At lower temperature, $\Delta S$ +ve hence $\Delta G$ = +ve. But at high temperature, $T \Delta S$ will be greater than
$\Delta H$, hence $\Delta G$ = -ve, spontaneous.
Ans : (A)
answered Mar 18, 2014