Question

For the reaction 2cl(g)-cl2(g),what are the signs of

Answer 1

The Cl2 is the more preferred state for 2 Cl atoms, it has a lower energy state than 2 single Cl atoms. So energy would be given off by the reaction. According to the sign conventions, that makes ΔH negative. And since Cl2 is more ordered than two single Cl atoms, its entropy increases, making ΔS positive.