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Unit 5 Organic Chemistry Reactions
Benzene
Combustion

In excess air, benzene burns to form carbon dioxide and water.

C 6H 6 + 71
2O2 6CO2 + 3H 2O


In limited air, it burns with a smoky flame forming carbon and water.

C 6H 6 + 11
2O2 6C + 3H…

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Nitration - when concentrated nitric acid, and a catalyst of concentrated sulphuric acid are
warmed together at 60 degrees under reflux, nitrobenzene and water are formed. The
electrophile is the ­NO2 group, which is formed by a protonated nitric acid molecule. (below
55 degrees, the reaction is too slow, above…

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Sulfonation ­ benzene reacts with fuming sulphuric acid at 40 degrees under reflux. The
electrophile is the SO3. The products are benzesulphonic acid and water:




Alkenes ­ benzene adds onto alkenes to form a branched chain alkane substituted into the
benzene ring (except with ethene, as it has too few…

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Reacts with concentrated nitric acid, more nitro groups substitute to give
2,4,6-trinitrophenol




Phenol as an acid

Water ­ forms the phenate ion:

C 6H 5OH + H 2O H 3O+ + C 6H 5O-

Sodium hydroxide ­ reacts in a neutralisation reaction to form the salt sodium phenate and
water…

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Acid chlorides, aromatic ­ reacts in aqueous solution to create C6H5O- ions, which are a
stronger nucleophile than phenol molecules.


Benzoic Acid
When warmed with concentrated nitric and sulphuric acids, 3-nitrobenzoic acid and water are
formed.


2-methlynitrobenzene
Preparation

Add the nitrating mixture, consisting of concentrated nitric and sulphuric acids, and…

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Reduction of a nitrile/amide ­ reduced by LiAlH4 in dry ether, then hydrolysis of the adduct
with dilute acid



As a Base

Water ­ they react reversibly, forming OH- ions
Acids ­ when reacted with an acid, a salt is formed.

With Acid Chlorides

A lone pair of electrons on…

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The tin (Sn) acts as a catalyst. It is oxidised to provides the electrons used to reduce the
nitrobenzene in the presence of the acid.




To remove the extra hydrogen from the ­NH3 group, sodium hydroxide solution is added in
excess:




Finally, the mixture is steam distilled by blowing steam…

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Acid chloride - Reacts with, like an aliphatic primary amine, an acid chloride to form a
secondary amine. The phenylamine acts as a nucleophile




Nitrous acid ­ nitrous acid is unstable, and has to be made is situ by mixing a solution of
sodium nitrate, NaNO2 with excess dilute hydrochloric…

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Phenylamine ­ with vigorous shaking, a yellow precipitate is formed:




Amides
Preparation

Ammonia and an acid chloride



Hydrolysis

When boiled under reflux with either aqueous acid or alkali, amides are hydrolysed. E.g.
ethanamide hydrolysed with dilute acid:



Polyamides

Condensation polymerisation ­ formed from two different monomers, each with two
identical…

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E.g poly(ethanol) ­ the monomer does not exist. The polymer is
manufactured by reacting the polymer polyvinylacetate with methanol in a transesterification
reaction.

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