According to the second law of thermodynamics,which of the following is true for a spontaneous process?

When $2 \ mol$ of an ideal gas $\left( C_{p,m} = \frac{5}{2} R \right)$ is heated from $300 \ K$ to $600 \ K$ at constant pressure,the change in entropy of the gas $\left( \Delta S \right)$ is:

For the oxidation of iron:
$4 Fe_{(s)} + 3 O_{2(g)} \rightarrow 2 Fe_2O_{3(s)}$
The entropy change is $-549.4 \ J \ K^{-1} \ mol^{-1}$ at $298 \ K$. Despite the negative entropy change of this reaction,why is the reaction spontaneous?
($\Delta_r H^\Theta$ for this reaction is $-1648 \times 10^3 \ J \ mol^{-1}$)

For the reaction $A + B \rightarrow C + D + q$,which has a positive entropy change,the reaction:

When naphthalene is heated strongly,it undergoes sublimation. What happens to the entropy of the system?

$A$ reversible adiabatic process is one in which: