Chemistry · Hydrocarbons
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The resonance energy of benzene is:
- A
-119.5 kJ/mol
- B
-358.5 kJ/mol
- C
+150.5 kJ/mol
- D
-208 kJ/mol
Resonance energy is the difference between the actual enthalpy of hydrogenation of benzene (-208 kJ/mol) and the theoretical enthalpy calculated for a hypothetical "cyclohexatriene" molecule (3x-119.5-358.5 kJ/mol). The difference, 150.5 kJ/mol, represents the extra stability due to resonance, which is called resonance energy.
This value does not represent the resonance energy but rather the enthalpy change for hydrogenation of the hypothetical cyclohexatriene structure. Therefore, this option is incorrect.
This option represents the total enthalpy change for hydrogenation of benzene, which is not the resonance energy. The resonance energy is calculated differently, making this option incorrect.
This value accurately represents the resonance energy of benzene, highlighting the extra stability that benzene gains from resonance compared to the hypothetical cyclohexatriene structure. Thus, this option is correct.
This value indicates the enthalpy of hydrogenation for benzene itself, not its resonance energy. While it is related to the question, it does not represent the actual resonance energy value, making this option incorrect.
Tagged under Chemistry · Hydrocarbons · 2024