Two statements are given below.
Statement I: Adsorption of a gas on the surface of charcoal is primarily an exothermic process.
Statement II: A closed vessel containing \( O_2(g) \), \( H_2(g) \), \( Cl_2(g) \), \( NH_3(g) \) has a pressure of 9 atm. About 1 g of charcoal was added to this vessel and after some time its pressure is \( P' \) atm. It is observed that \( P'>P \).
Choose the correct answer.