1. flat hexagonal 6 carbon ring 2. each carbon is bonded to one hydrogen and two carbon 3 fourth carbon electron is delocalised 4. p orbitals overlap to make pi bond 5. electrons are delocalised
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What are three characteristics of Benzene?
colourless, sweet smelling, carcinogenic
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What is kekules structure of Benzene?
6 ring of carbon atoms joined by alternating single/double bonds
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what are three pieces of evidence against the Kekule structure of Benzene?
1. lack of reactivity under normal conditions meaning no C=C bonds 2. kekule suggests that benzene has different bond lengths 3. benzene should have hydrogenation enthalpy of -360 but has -208
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what is proof of the same bond lengths?
X-ray diffraction
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Why is benzene so resistant to reactions? (3)
Benzene has a ring of delocalised electrons with a low electron density meaning it it stable and cannot polarise reactions
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What are the four main reactions of Benzene? (4)
Nitration, Halogenation, alkylation, acylation
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What are the conditions for the nitration of benzene?
50C water bath, concentrated sulphuric acid, concentrated nitric acid
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What catalyst do the other reactions use?
Halogen carrier e.g. FeBr3 or AlCl3
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What is the mechanism of reaction for the nitration of Benzene?
fill in
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What is the mechanisms of reaction for the halogenation of benzene?
fill in
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What is the mechanism of reaction for the alkylation of benzene?
fill in
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What is the mechanism of reaction for the acylation of benzene?
fill in
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What is phenol?
a benzene ring with an -OH group attached
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what is the solubility of phenol compared to alcohols?
Phenol is less soluble than other alcohols due to the non-polar benzene ring
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Why is phenol a weak acid?
in water the phenol formes a phenoxide ions and a proton
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What are the three reactions of phenol?
1.sodium hydroxide 2. bromination 3. nitratipno
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What is formed in the bromination of phenol?
white precipitate.
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What are the two products of nitration of phenol?
2-nitrophenol 4-nitrophenol
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what is the reaction mechanism of phenol with sodium hydroxide
fill in
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what is the reaction mechanism of phenol with bromine
fill in
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What is the reaction of phenol with nitric acid
fill in
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compare the reactivity of phenol and benzene?
phenol is more reactive than benzene as the lone pair of electrons from the oh group are donated into the pi bonds. electron density is increased and attract electrophiles
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What are the activating groups?
2,4 ortho and para directing
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What are the deactivating groups?
3 meta directing
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What are the 5 2,4 directing groups?
NH, OH, OR, Alkyl, halogen
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What are the 8 3 directing groups?
RCOR, COOR, SO3H, CHO, COOH,CN,NO2, NR3+
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Other cards in this set
Card 2
Front
What are three characteristics of Benzene?
Back
colourless, sweet smelling, carcinogenic
Card 3
Front
What is kekules structure of Benzene?
Back
Card 4
Front
what are three pieces of evidence against the Kekule structure of Benzene?
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