For a process,entropy change of a system is expressed as

For a reversible spontaneous change,$\Delta S$ is:

If the enthalpy change for the following reaction at $300 \ K$ is $+7 \ kJ \ mol^{-1}$,find the entropy change of the surrounding (in $J \ K^{-1}$)?
$H_2O_{(s)} \longrightarrow H_2O_{(l)}$

In which of the following processes does entropy decrease?

When a solid is converted into liquid,entropy

For an endothermic reaction $A \rightarrow B$ to occur spontaneously at a constant temperature $T$,the entropy change $\Delta S$ must be: