What type of organic compound contains the functional group –NH2?
Primary Amine
Amines are derivatives of ammonia where hydrogen atoms are replaced by alkyl or aryl groups.
What type of amine is formed when ammonia reacts with a halogenoalkane?
Primary amine
The halogen atom is replaced by an –NH2 group.
Fill in the blank:
Reaction of a halogenoalkane with ammonia is an example of _______ substitution.
nucleophilic
Ammonia acts as a nucleophile donating a lone pair.
True or False:
Nitriles can be reduced to form primary amines.
True
Reduction adds hydrogen across the C≡N bond.
What functional group must be reduced to convert a nitrile into a primary amine?
Nitrile group
The –C≡N group is reduced to –CH2NH2.
Fill in the blank:
The reduction of nitriles to amines requires the addition of _______.
hydrogen
The triple bond is reduced to a single bond.
True or False:
Aromatic amines can be prepared by reducing nitro compounds.
True
The nitro group (–NO2) is converted to an amine group (–NH2).
What type of compounds are aromatic amines commonly used to manufacture?
Dyes
Many synthetic dyes are produced from aromatic amines.
Fill in the blank:
The nitro group in aromatic compounds is represented as _______.
–NO2
Reduction converts it to –NH2.
What reagent is commonly used to reduce nitro compounds to aromatic amines in the laboratory?
Tin and hydrochloric acid
The amine is then released by adding alkali.
True or False:
Ammonia acts as a nucleophile when reacting with halogenoalkanes.
True
It donates a lone pair of electrons to the carbon atom.
Why are aromatic amines important in industrial chemistry?
Dye manufacture
They are key intermediates in producing coloured compounds.
What type of chemical behaviour do amines exhibit in aqueous solution?
Weak bases
Amines accept protons using the lone pair on the nitrogen atom.
What particle allows amines to act as bases?
Lone pair on nitrogen
The lone pair can accept a proton (H+).
Fill in the blank:
Amines act as bases because the nitrogen atom has a _______ pair of electrons.
lone
This pair can bond with H+ to form an ammonium ion.
True or False:
Amines react with acids to form ammonium salts.
True
The amine accepts a proton from the acid.
Which compound is generally the weakest base: ammonia, primary aliphatic amine, or primary aromatic amine?
Primary aromatic amine
Delocalisation of the lone pair reduces its availability.
True or False:
Primary aliphatic amines are stronger bases than ammonia.
True
Alkyl groups donate electron density to nitrogen.
Fill in the blank:
Alkyl groups increase the basic strength of amines by _______ electron density to nitrogen.
donating
This makes the lone pair more available to accept a proton.
Why are aromatic amines weaker bases than aliphatic amines?
Lone pair delocalisation
The lone pair interacts with the benzene ring π system.
True or False:
In aromatic amines, the nitrogen lone pair is partially delocalised into the benzene ring.
True
This reduces its ability to bond with H+.
Fill in the blank:
When an amine accepts a proton, it forms an _______ ion.
ammonium
The nitrogen atom gains a positive charge.
What factor mainly determines the basic strength of amines?
Availability of lone pair
The more available the lone pair, the stronger the base.
Why do primary aliphatic amines act as stronger bases than aromatic amines?
Electron-donating alkyl groups
Alkyl groups increase electron density on nitrogen.
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3.1.1 Atomic structure50
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3.1.2 Amount of substance47
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3.1.3 Bonding90
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3.1.4 Energetics62
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3.1.5 Kinetics55
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3.1.6 Equilibria & Kc24
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3.1.7 Redox equations17
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3.1.8 Thermodynamics27
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3.1.9 Rate equations24
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3.1.10 Kp12
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3.1.11 Electrode potentials46
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3.1.12 Acids and bases69
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3.2.1 Periodicity22
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3.2.2 Group 2 metals24
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3.2.3 Group 7 (halogens)31
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3.2.4 Period 3 oxides35
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3.2.5 Transition metals95
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3.2.6 Ions in aqueous solution39
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3.3.1 Intro to organic chemistry42
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3.3.2 Alkanes49
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3.3.3 Halogenoalkanes36
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3.3.4 Alkenes36
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3.3.5 Alcohols43
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3.3.6 Organic analysis36
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3.3.7 Optical isomerism12
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3.3.8 Aldehydes & ketones20
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3.3.9 Carboxylic acids & derivatives25
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3.3.10 Aromatic chemistry29
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3.3.11 Amines41
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3.3.12 Polymers24
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3.3.13 Amino acids, proteins, DNA61
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3.3.14 Organic synthesis12
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3.3.15 NMR spectroscopy14
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3.3.16 Chromatography12
