For the reaction $A \to B$,$\Delta H = 4 \, kcal \, mol^{-1}$ and $\Delta S = 10 \, cal \, K^{-1} \, mol^{-1}$. At what temperature $(K)$ will the reaction become spontaneous?

$A$ reaction,$A + B \rightarrow C + D + q$,is found to have a positive entropy change. The reaction will be:

For a chemical reaction,if $\Delta H = \Delta S > 0$,then $\Delta H = $ ................

Data given for the following reaction is as follows:
$FeO_{(s)} + C_{(\text{graphite})} \longrightarrow Fe_{(s)} + CO_{(g)}$

Substance	$\Delta H^{\circ} \text{ (kJ mol}^{-1})$	$\Delta S^{\circ} \text{ (J mol}^{-1} \text{ K}^{-1})$
$FeO_{(s)}$	$-266.3$	$57.49$
$C_{(\text{graphite})}$	$0$	$5.74$
$Fe_{(s)}$	$0$	$27.28$
$CO_{(g)}$	$-110.5$	$197.6$

The minimum temperature in $K$ at which the reaction becomes spontaneous is ....... .
(Integer answer)

For the reaction at $298 \ K$,$2 \ A^{+}B \rightarrow C$. $\Delta H = 400 \ kJ \ mol^{-1}$ and $\Delta S = 0.2 \ kJ \ mol^{-1} \ K^{-1}$. The reaction will become spontaneous above $...... \ K$.

Spontaneity of a chemical reaction is decided by the negative change in