The spontaneous nature of a reaction is impossible if

For a reaction at $25^o C$,$\Delta H > 0$ and $\Delta S > 0$. Under what conditions will this reaction become spontaneous?

For an irreversible process occurring at constant $T$ and $P$,where only pressure-volume work is involved,which condition for entropy change $(\Delta S)$ and Gibbs free energy change $(\Delta G)$ is satisfied?

The entropy and enthalpy changes for the reaction $CO_{(g)} + H_2O_{(g)} \rightleftharpoons CO_{2(g)} + H_{2(g)}$ at $300 \ K$ and $1 \ atm$ are respectively $-42.4 \ J \ K^{-1}$ and $-41.2 \ kJ$. The temperature at which the reaction will go in the reverse direction is (in $K$)

For a spontaneous reaction at all temperatures, which of the following is correct?

For the reaction $CaCO_3(s) \rightarrow CaO(s) + CO_2(g)$ at $298 \ K$ and $1 \ atm$ pressure,the values of $\Delta H^o$ and $\Delta S^o$ are $+179.1 \ kJ \ mol^{-1}$ and $+160.2 \ J \ K^{-1} \ mol^{-1}$ respectively. Assuming that $\Delta H^o$ and $\Delta S^o$ do not change with temperature,at what temperature (in $K$) will the process become spontaneous?