Heat of Hydrogenation of 1,3-Butadiene
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Heat of Hydrogenation of CH3-CH=CH2
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The heat of hydrogenation is a measure of the energy released when one mole of a compound undergoes hydrogenation. In this case, we are given that the heat of hydrogenation of CH3-CH=CH2 is -30 kcal/mol.

Resonance Energy of 1,3-Butadiene
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Resonance energy is the stabilizing energy associated with the delocalization of electrons in a molecule due to resonance. It is a measure of the stability of the molecule. In this case, we are given that the resonance energy of 1,3-butadiene is 3 kcal/mol.

Explanation
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The heat of hydrogenation can be related to the resonance energy of a compound using the following equation:

Heat of Hydrogenation = 2 × Resonance Energy

This equation holds true for compounds that can undergo resonance stabilization. In the case of 1,3-butadiene, the molecule can undergo resonance stabilization due to the delocalization of pi electrons. This resonance stabilization results in a lower energy state and increased stability of the molecule.

Since the resonance energy of 1,3-butadiene is 3 kcal/mol, we can calculate the heat of hydrogenation as follows:

Heat of Hydrogenation = 2 × 3 kcal/mol
Heat of Hydrogenation = 6 kcal/mol

Therefore, the heat of hydrogenation of 1,3-butadiene is 6 kcal/mol.

Explanation of the Equation
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The relationship between the heat of hydrogenation and the resonance energy can be explained by considering the reaction mechanism of hydrogenation. During hydrogenation, a molecule adds two hydrogen atoms across the double bond, resulting in the formation of a single bond. This process releases energy.

In the case of 1,3-butadiene, the molecule can exist in two resonance forms. These resonance forms differ only in the arrangement of pi electrons. The resonance energy is the energy associated with the stabilization of the molecule due to the delocalization of pi electrons.

When 1,3-butadiene undergoes hydrogenation, the double bonds are converted into single bonds, and the pi electrons are no longer delocalized. This results in a loss of resonance energy. The heat of hydrogenation is a measure of the energy released during this process.

Conclusion
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The heat of hydrogenation of 1,3-butadiene can be calculated using the equation Heat of Hydrogenation = 2 × Resonance Energy. In this case, the heat of hydrogenation is found to be 6 kcal/mol. The resonance energy of a compound is an important factor in determining its stability and reactivity.