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If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hydrogenation of cyclohexene and benzene, then the resonance energy of benzene in kJ/mol is (In integer)
Correct answer is '152'. Can you explain this answer?
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If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hy...
Given:
Heat of hydrogenation of cyclohexene = 208 kJ/mol
Heat of hydrogenation of benzene = 120 kJ/mol
Resonance Energy:
Resonance energy is the difference in energy between the actual energy of a molecule and the energy that would be expected based on its localized structure. In the case of benzene, resonance energy is a measure of the stability provided by the delocalized π-electron system.
Calculating Resonance Energy:
To calculate the resonance energy of benzene, we need to compare its observed heat of hydrogenation with the expected heat of hydrogenation based on its localized structure.
Localized Structure of Benzene:
Benzene can be represented by a resonance hybrid of two Kekulé structures, where each carbon is sp2 hybridized and forms a σ bond with two neighboring carbons and a hydrogen atom.
Expected Heat of Hydrogenation:
Each double bond in benzene is equivalent to a cyclohexene double bond, which has an observed heat of hydrogenation of 208 kJ/mol. Therefore, based on the localized structure, we would expect the heat of hydrogenation of benzene to be 3 times that of cyclohexene (3 double bonds in benzene).
Expected heat of hydrogenation of benzene = 3 * 208 kJ/mol = 624 kJ/mol
Resonance Energy Calculation:
Resonance energy = Expected heat of hydrogenation - Observed heat of hydrogenation
Resonance energy = 624 kJ/mol - 120 kJ/mol = 504 kJ/mol
Therefore, the resonance energy of benzene is 504 kJ/mol.
However, the correct answer given is '152'. There might be a mistake in the given data or a different approach to calculate the resonance energy has been used. Without further information, it is not possible to determine the exact method used to obtain the answer '152'.
Heat of hydrogenation of cyclohexene = 208 kJ/mol
Heat of hydrogenation of benzene = 120 kJ/mol
Resonance Energy:
Resonance energy is the difference in energy between the actual energy of a molecule and the energy that would be expected based on its localized structure. In the case of benzene, resonance energy is a measure of the stability provided by the delocalized π-electron system.
Calculating Resonance Energy:
To calculate the resonance energy of benzene, we need to compare its observed heat of hydrogenation with the expected heat of hydrogenation based on its localized structure.
Localized Structure of Benzene:
Benzene can be represented by a resonance hybrid of two Kekulé structures, where each carbon is sp2 hybridized and forms a σ bond with two neighboring carbons and a hydrogen atom.
Expected Heat of Hydrogenation:
Each double bond in benzene is equivalent to a cyclohexene double bond, which has an observed heat of hydrogenation of 208 kJ/mol. Therefore, based on the localized structure, we would expect the heat of hydrogenation of benzene to be 3 times that of cyclohexene (3 double bonds in benzene).
Expected heat of hydrogenation of benzene = 3 * 208 kJ/mol = 624 kJ/mol
Resonance Energy Calculation:
Resonance energy = Expected heat of hydrogenation - Observed heat of hydrogenation
Resonance energy = 624 kJ/mol - 120 kJ/mol = 504 kJ/mol
Therefore, the resonance energy of benzene is 504 kJ/mol.
However, the correct answer given is '152'. There might be a mistake in the given data or a different approach to calculate the resonance energy has been used. Without further information, it is not possible to determine the exact method used to obtain the answer '152'.
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Community Answer
If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hy...
Resonance energy is the difference between the hydrogenation energy of three 'non-resonance' double bonds and the measured hydrogenation energy.
i.e. (3 × 120) − 208 = 152 kJ/mol
i.e. (3 × 120) − 208 = 152 kJ/mol
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If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hydrogenation of cyclohexene and benzene, then the resonance energy of benzene in kJ/mol is (In integer)Correct answer is '152'. Can you explain this answer?
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If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hydrogenation of cyclohexene and benzene, then the resonance energy of benzene in kJ/mol is (In integer)Correct answer is '152'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hydrogenation of cyclohexene and benzene, then the resonance energy of benzene in kJ/mol is (In integer)Correct answer is '152'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hydrogenation of cyclohexene and benzene, then the resonance energy of benzene in kJ/mol is (In integer)Correct answer is '152'. Can you explain this answer?.
If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hydrogenation of cyclohexene and benzene, then the resonance energy of benzene in kJ/mol is (In integer)Correct answer is '152'. Can you explain this answer? for JEE 2024 is part of JEE preparation. The Question and answers have been prepared according to the JEE exam syllabus. Information about If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hydrogenation of cyclohexene and benzene, then the resonance energy of benzene in kJ/mol is (In integer)Correct answer is '152'. Can you explain this answer? covers all topics & solutions for JEE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for If 208 kJ/mol and 120 kJ/mol respectively are the observed heats of hydrogenation of cyclohexene and benzene, then the resonance energy of benzene in kJ/mol is (In integer)Correct answer is '152'. Can you explain this answer?.
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