The correct thermodynamic conditions for a spontaneous reaction at all temperatures are:

Which of the following pairs of a chemical reaction is certain to result in a spontaneous reaction?

Which of the following conditions are not suitable for a spontaneous reaction?

For a reaction at $25\,^oC$,the enthalpy change $(\Delta H)$ and entropy change $(\Delta S)$ are $-11.7 \times 10^3\, J \, mol^{-1}$ and $-105 \, J \, mol^{-1} K^{-1}$ respectively. The reaction is:

Which of the following processes will never be a spontaneous process?

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