For a given reaction, $\Delta {\rm{H}} = 35.5{\rm{ KJ \;mo}}{{\rm{l}}^{ - 1}}$ and $\Delta {\rm{S}} = 83.6\,{\rm{J}}{{\rm{K}}^{ - 1}}{\rm{ mo}}{{\rm{l}}^{ - 1}}.$ The reaction is spontaneous at : (Assume that $\Delta {\rm{H}}$ and $\Delta {\rm{S}}$ do not vary with temperature)

${\rm{T}} > {\rm{425}}\,{\rm{K}}$

${\rm{T}} < {\rm{425}}\,{\rm{K}}$

NEET UG CHEMISTRY MCQ: THERMODYNAMICS

1 Easy

1 of 1

Application +4 | -1

For a given reaction,

\Delta \mathrm{H} = 35.5\mathrm{ KJ \;mo}{\mathrm{l}^{ - 1}}

and

\Delta \mathrm{S} = 83.6\,\mathrm{J}{\mathrm{K}^{ - 1}}\mathrm{ mo}{\mathrm{l}^{ - 1}}.

The reaction is spontaneous at : (Assume that

\Delta \mathrm{H}

and

\Delta \mathrm{S}

do not vary with temperature)

View answer and explanation

Correct option: C

\mathrm{T} > \mathrm{425}\,\mathrm{K}

Option C (

\mathrm{T} > \mathrm{425}\,\mathrm{K}

) is correct because for a reaction to be spontaneous,

\Delta G

must be negative, and this occurs when

T > \frac{{\Delta H}}{{\Delta S}}