Heat evolved in the reaction

Explanation:

                              H2 + Cl2→ 2HCl

Let us consider the energy of HCl = x.

The total energy in the above reaction-
 
                  Energy of H2 + energy of Cl2 = 2  energy of HCl -

                  430 KJ/mol + 242 KJ/mol = 2x (- 182) KJ/mol

                  672 + 182 = 2x

                  2x = 854

                  x = 427 KJ/mol

So, the energy of the H-Cl bond is 427 KJ/mol.

Final Answer:
Hence, Option (B) is correct.