What is the nature of the reaction at $298 \ K$,if the entropy change and enthalpy change for a chemical reaction are $7.4 \ cal \ K^{-1}$ and $-2.5 \times 10^3 \ cal$,respectively?

Compare the following criteria for spontaneity of a reaction based on the values of $\Delta_{\text{r}}H^0$,$\Delta_{\text{r}}S^0$,and $\Delta_{\text{r}}G^0$:

$\Delta_{\text{r}}H^0$	$\Delta_{\text{r}}S^0$	$\Delta_{\text{r}}G^0$	Description
$(a) (+)$	$(-)$	$(+)$	$(i) \text{ Non-spontaneous at all temperatures}$
$(b) (-)$	$(-)$	$(-)$	$(ii) \text{ Spontaneous at low temperatures}$
$(c) (-)$	$(+)$	$(-)$	$(iii) \text{ Spontaneous at all temperatures}$

The standard entropy change for the reaction $4 Fe ( s ) + 3 O_{2} ( g ) \rightarrow 2 Fe_{2} O_{3} ( s )$ is $-550 \ J K^{-1}$ at $298 \ K$. Given: The standard enthalpy change for the reaction is $-165 \ kJ \ mol^{-1}$. The temperature in $K$ at which the reaction attains equilibrium is ... . (Nearest Integer)

$2 \, mol$ of zinc is dissolved in $HCl$ at $25 \, ^oC$. What is the work done in an open vessel?

$A$ spontaneous process is impossible if ........

For a reaction to be spontaneous,the required conditions are