For a reaction to be spontaneous,the required conditions are

  • A
    $\Delta_r H^{\circ} = -ve, \Delta_r S^{\circ} = -ve, \text{ at high } T$.
  • B
    $\Delta_r H^{\circ} = +ve, \Delta_r S^{\circ} = +ve, \text{ at high } T$.
  • C
    $\Delta_r H^{\circ} = +ve, \Delta_r S^{\circ} = +ve, \text{ at low } T$.
  • D
    $\Delta_r H^{\circ} = +ve, \Delta_r S^{\circ} = -ve, \text{ at all } T$.

Explore More

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 $\text{ K}$)?

For the reaction at $298 \, K$,$2 A + B \rightarrow C$. Given $\Delta H = 400 \, kJ \, mol^{-1}$ and $\Delta S = 0.2 \, kJ \, K^{-1} \, mol^{-1}$. At what temperature will the reaction become spontaneous,considering $\Delta H$ and $\Delta S$ to be constant over the temperature range?

Which of the following is correct?

Calculate the amount of work done during isothermal expansion of a gas from a volume of $4 \ dm^{3}$ to $6 \ dm^{3}$ against a constant external pressure of $3 \ atm$ (in $J$)?

Calculate $\Delta H_f^o$ for $UBr_4$ from the $\Delta G^o$ of reaction and the $S^o$ values: $U_{(s)} + 2Br_2(\ell) \to UBr_{4(s)}$; $\Delta G^o = -788.6 \ kJ$; $S^o \ (J/K \cdot mol): U_{(s)} = 50.3, Br_2(\ell) = 152.3, UBr_{4(s)} = 242.6$.

Vedclass Products

For Students

Vedclass Test Series

Mock tests in real JEE/NEET style with performance analysis. 5-day free trial.

Start Free Trial
For Teachers

Exam Paper Generator

Generate Set A/B/C/D exam papers from 7.5L+ questions in 2 minutes. 3 chapters free.

Try Free
For Institutes

Online Exam Module

Live online exams with unlimited students, 360° analytics & white-label branding.

See Demo