# 6.18   For the reaction,  $2 Cl (g) \rightarrow Cl_2 ( g)$, what are the signs of  $\Delta H \: \: and \: \: \Delta S$ ?

The given reaction represents the formation of a chlorine molecule from its atom. Bond formation taking place, therefore the energy is released during this. So, $\Delta H$ is negative.
Two moles of an atom have more randomness than the one mole of chlorine. So, spontaneity is decreased. Hence $\Delta S$ is negative.