Problem: Use bond enthalpies in the table below to estimate ΔHrxn for each of the following reactions.Average Bond Enthalpies (kJ/mol)C-H 413N-H 391O-H 463F-F 155C-C 348N-N 163O-O 146C=C 614N-O 201O=O 495Cl-F 253C-N 293N-F 272O-F 190Cl-Cl 242C-O 358N-Cl 200O-Cl 203Br-F 237C=O 799N-Br 243O-I 234Br-Cl 218C-F 485H-H 436Br-Br 193C-Cl 328H-F 567C-Br 276H-Cl 431I-Cl 208C-I 240H-Br 366I-Br 175H-I 299I-I 151

FREE Expert Solution

We are asked to calculate the enthalpy of reactions (ΔH_rxn).

To calculate the ΔH°_rxn using bond energies, we’re going to use the following equation:

$\boxed{\mathbf{∆}{\mathbf{H}}_{\mathbf{rxn}}\mathbf{=}{\mathbf{H}}_{\mathbf{bond}\mathbf{ }\mathbf{reactant}}\mathbf{-}{\mathbf{H}}_{\mathbf{bond}\mathbf{ }\mathbf{products}}}$

REACTION:

Average Bond Enthalpies (kJ/mol)
C-H 413		N-H 391		O-H 463		F-F 155
C-C 348		N-N 163		O-O 146
C=C 614		N-O 201		O=O 495		Cl-F 253
C-N 293		N-F 272		O-F 190		Cl-Cl 242
C-O 358		N-Cl 200		O-Cl 203		Br-F 237
C=O 799		N-Br 243		O-I 234		Br-Cl 218
C-F 485		H-H 436				Br-Br 193
C-Cl 328		H-F 567
C-Br 276		H-Cl 431				I-Cl 208
C-I 240		H-Br 366				I-Br 175
		H-I 299				I-I 151

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