For the transformation $C(\text{graphite}) \rightarrow C(\text{diamond})$,$\Delta S$ is .......

What is the unit of entropy?

At $25\,^oC$ and $1\,atm$ pressure,mercury reacts with chlorine to form mercurous chloride: $2Hg + Cl_2 \to Hg_2Cl_2; \Delta H = -31.3\,kcal$. What is the entropy change of the reaction at $25\,^oC$?

The entropy values (in $J \, K^{-1} \, mol^{-1}$) of $H_{2(g)} = 130.6$,$Cl_{2(g)} = 223.0$,and $HCl_{(g)} = 186.7$ at $298 \, K$ and $1 \, atm$ pressure. Then entropy change for the reaction $H_{2(g)} + Cl_{2(g)} \to 2HCl_{(g)}$ is

For a spontaneous process,

What is entropy? Explain its role in spontaneity.