3.10 Aromatic chemistry Flashcards

1
Q

Explain why the structure of Benzene is more stable than the proposed Kekule structure (6)

A
  1. Bond length in Benzene is 139pm this is between the length of single and double C-C bonds so it cannot contain simple C-C or C=C bonds. Stability is due to delocalised electrons
  2. Enthalpy of hydrogenation of cyclohex-1-ene was -120kJ/mol (this is for one C=C) so expected value for hydrogenation of Benzene would be 120 X 3 = -360kJ/mol however the actual value is -208kJ/mol so more energy is required to break the bonds in benzene so it must be more stable
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1
Q

Formula of Benzene

A

c6h6

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2
Q

What was Kekule’s proposed structure of benzene

A

Cyclical 6 carbon compound with each carbon attached to 1 H. 3 double CC bonds and 3 single CC bonds which alternate

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3
Q

In what orbital are the delocalised electrons in Benzene in?

A

P

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4
Q

What type of reaction do arenes undergo

A

Electrophilic substitution

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5
Q

Name the reaction that produces a strong electrophile for acylation

A

RCOCl + AlCl3 > RCO+ AlCl4-

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6
Q
A
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