Reverse activation energy from forward Ea and ΔH

Steps:

• Identify forward activation energy (Ea_forward) as the energy barrier from reactants to transition state: 447 kJ/mol.
• Determine enthalpy change (ΔH) for the forward reaction as endothermic: +283 kJ/mol.
• Apply the formula for reverse activation energy: Ea_reverse = Ea_forward - ΔH.
• Calculate: 447 kJ/mol - 283 kJ/mol = 164 kJ/mol.

Why D is correct:

• It matches Ea_reverse = Ea_forward - ΔH, per the definition of activation energies in reaction energy diagrams.

Why the others are wrong:

• A: Negative activation energy is impossible, as it represents an energy barrier.
• B: Likely a miscalculation, such as subtracting an incorrect value from Ea_forward.
• C: Equals ΔH, not the reverse energy barrier.

Final answer: D