The second law of thermodynamics states that in a cyclic process:

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 $-1648 \times 10^3 \ J \ mol^{-1}$)

$A$ reversible adiabatic process is one in which:

Calculate the entropy change for melting $1 \ g$ of ice at $0^{\circ} C$ in $J \ g^{-1} K^{-1}$,if the heat of fusion of ice at $0^{\circ} C$ is $80 \ J \ g^{-1}$.

When a solid melts reversibly,which of the following occurs?

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