The enthalpy of vaporization of water at $298 \ K$ is $386 \ kJ \ mol^{-1}$. What is the entropy of vaporization of water in $kJ \ K^{-1} \ mol^{-1}$?

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

Which of the following processes is non-spontaneous?

The process with negative entropy change is

The entropy of a sample of a certain substance increases by $0.836 \ J \ K^{-1}$ on adding reversibly $0.3344 \ J$ of heat at constant temperature. The temperature of the sample is.....$K$

The change in entropy is negative for which of the following processes?