Assertion: Many endothermic reactions that ar | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(C) For a reaction to be spontaneous,the Gibbs free energy change $\Delta G$ must be negative,where $\Delta G = \Delta H - T\Delta S$.For endothermic

Vedclass · Accepted Answer

If the Assertion is correct but Reason is incorrect.

Vedclass · Answer

(C) For a reaction to be spontaneous,the Gibbs free energy change $\Delta G$ must be negative,where $\Delta G = \Delta H - T\Delta S$.For endothermic reactions,$\Delta H > 0$. If the reaction involves an increase in entropy $(\Delta S > 0)$,then at high temperatures,the term $T\Delta S$ becomes larger than $\Delta H$.Consequently,$\Delta G = \Delta H - T\Delta S$ becomes negative,making the reaction spontaneous at high temperatures.The reason provided is incorrect because the entropy of a system is generally considered a state function that does not necessarily increase with temperature in the context of the spontaneity condition; rather,the term $T\Delta S$ increases with temperature.

Assertion: Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature.
Reason: Entropy of the system increases with increase in temperature.

Similar Questions

For a certain reaction, $\Delta H^0 = -345 \text{ kJ}$ and $\Delta S^0 = -123 \text{ JK}^{-1}$. At what temperature will the change over from spontaneous to non-spontaneous occur (in $\text{ K}$)?

The signs of $\Delta_r H^{\circ}$ and $\Delta_r S^{\circ}$ for a reaction to be spontaneous at all temperatures respectively are

The reaction $MgO_{(s)} + C_{(s)} \to Mg_{(s)} + CO_{(g)}$,for which $\Delta_r H^o = +491.1 \ kJ \ mol^{-1}$ and $\Delta_r S^o = 198.0 \ J \ K^{-1} \ mol^{-1}$,is not feasible at $298 \ K$. The temperature above which the reaction will be feasible is ..... $K$.

Calculate $\Delta H^{\circ}$ for a reaction at $298 \ K$ if $\Delta S^{\circ} = 120 \ J \ K^{-1}$ and $\Delta G^{\circ} = 28000 \ J$. (in $kJ$)

The relation between $\Delta G$ and $\Delta H$ is

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Assertion: Many endothermic reactions that are not spontaneous at room temperature become spontaneous at high temperature.Reason: Entropy of the system increases with increase in temperature.