$A$ reversible adiabatic process is one in which:

For chemical reactions,the calculation of change in entropy is normally done:

Given the standard entropy values at $298 \ K$ and $1 \ atm$ as $H_2(g) : 130.6 \ J \ K^{-1} \ mol^{-1}$,$Cl_2(g) : 223.0 \ J \ K^{-1} \ mol^{-1}$,and $HCl(g) : 186.7 \ J \ K^{-1} \ mol^{-1}$,calculate the entropy change $(\Delta S^{\circ})$ in $J \ K^{-1} \ mol^{-1}$ for the reaction: $H_2(g) + Cl_2(g) \rightarrow 2HCl(g)$

$\Delta S_{surr}$ for an exothermic reaction is

Identify the correct statement regarding a spontaneous process.

For a spontaneous process,the correct statement is