Question

For a chemical reaction, $\Delta S=-0.035kJ/K$ and $\Delta H=-20kJ$. At what temperature does the reaction turn non-spontaneous?

• A. $<5.14K$
• B. $<57.14K$
• C. $<571.4K$
• D. $<5714.0K$

Answer 1

The correct option is C $<571.4K$

For a reaction to turn non-spontaneous:

$\Delta G>0$

$\Delta H-T\Delta S>0$

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

$\frac{20000}{35}>T$

$T<571.4K$