Question

For the reaction, $2Cl(g)→Cl_2(g)$, what are the signs of $∆H$ and $∆S$ ?

Answer 1

$∆H$and $∆S$ are negative.
The given reaction represents the formation of chlorine molecule from chlorine atoms. Here, bond formation is taking place. Therefore, energy is being released. Hence, $∆H$ is negative.
Also, two moles of atoms have more randomness than one mole of a molecule. Since spontaneity is decreased, $∆S$ is negative for the given reaction.