The bond energy of a carbon-carbon C-C single bond in ethane C2H6 is approximately 348 kJ/mol.When two ethane molecules react to form one butane molecule C4H10 , the reaction can be represented as follows:2 C2H6 C4H10In this reaction, one C-C bond is formed, and no C-C bonds are broken. Since the bond energy of a C-C bond is 348 kJ/mol, the energy change for this reaction would be the energy released when the new C-C bond is formed.Energy change = -1 Energy of C-C bond formed Energy change = -1 348 kJ/mol Energy change = -348 kJ/molThe energy change for this reaction is -348 kJ/mol, which means that 348 kJ/mol of energy is released when two ethane molecules react to form one butane molecule.