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3 Cards in this Set
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1)Benzene C₆H₆ is the simplest aromatic hydrocarbon
a) Discuss the structure in bonding present in benzene (4) |
> Benzene has bond angles of 120⁰.
> A Diagram showing the structure of benzene and bonds present. > C-C bonds at equal lengths. > A delocalised electron system is present. > A Hexagonal Structure. |
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b) Cyclohexane reacts with hydrogen to form cyclohexane:
C₆H₁₀ + H₂ --> C₆H₁₂ ∆H = -120 kJmol⁻1 Calculate the enthalpy change of the hydrogenation of benzene to cyclohexane, assuming it has the cyclohexatriene structure (3 double bonds in a chain)(1) |
-120 x 3 = -360 kJmol⁻1
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c) The experimental valur for the hydrogenation of benzene is -207 kJmol⁻1. Explain why this value differs from the calculated value in b)(1)
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Benzene has a delocalised electron system making the structure more stable and harder to break.
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