It has a functional group of NH2.
GENERAL MOLECULAR FORMULAR/STRUCTURE
It has a general molecular formula of RNH2 or structure of R – N – H
They are derivatives of ammonia where one or more hydrogen atoms have been replaced by alkyl or aryl groups e.g. RNHz, R2NH.
Amines can be classified according to alkyl group.
- Primary amine with one alkyl group e.g. RNH2 or
R or CH3
H N H H N H
- Secondary amine with 2 alkyl groups e.g. R2NH or
R N or CH3 N H
- Tertiary amine with 3 alkyl groups e.g. R3N or
R1 N R11 or CH3 N CH3
- They can dissolve in water.
- They are gases and liquid.
- They have fishy odour.
- As bases they neutralize acids.
- They dissociate/ionize in water e.g. CH3NH2 + H2O CH3NH3++ OH–
- Used in making nylon
- They can also be used in making polyamide.
- State two (2) physical properties and two (2) chemical properties of amine.
- Give the classes of amine according to the number of their alkyl groups.
It has functional group of –C which is known as carbonamide group.
O H O
CH3 C or H C C
NH2 H N H
– Amide e.g. ethanmide can be derived from ethanoic acid in the presence of ammonia.
CH3 C + NH3 C + H2O CH3 – C + NH3 CH3 C +H2O
– Amide is commonly prepared by reacting esters with concentrated aqueous ammonia. E.gCH3COOC2H5 + NH3 Ethanamide CH3CONH2 + C2H5OH
-They can also be prepared by removing a molecule of water from ammonium salt of carboxylic x acids.
e.g. CH3COONH4 CH3CONH2 + H2O
- Only methanamide is a liquid while others are solid.
- They have high melting point and high boiling point.
- Amide can be hydrolysed in the presence of alkali and mineral acid e.g.
CH3CONH2 + H2O CH3COOH + NH3
- In the presence of sodium hydroxide and bromine, amides produce amines with elimination of one carbonyl group.
e.g.CH3CONH2 + Br2 + 4NaOH CH3NH2 + 2NaBr + Na2CO3 + 2H2O
- Used in the preparation of amines.
- Used in making synthetic resins and plastics.
- It can also be used in making fertilizer.
This is an amide of hydrogen trioxo carbonate (IV) acid. It is produced by compressing CO2 and NH3 at high pressure at 2000C.
O C O C
N.B.: Urea is produced in our body and excreted in the urine.
- Write the structural formula of amide.
- Give one different between amine and amide.
1.Tertiary amine is represented as follow
- R2NH2 B. (CH3)2NH C.R2NH3 D. R2N
2.Which of the following has fishy odour
- alkanoic acid B. alkanol C. amide D. amine
3.Amide can be regarded as derivatives of …………
- alkanol B. policarboxylic acid C. monocarboxylic acid D. carbonxamide group
4.During the hydrolysis of amides, one of the following is produced.
- monocarboxylic acids B. water C. H2SO4 D.NaOH
- Carbamide is an example of
- amine B. alkane C. alkyl D. amide
1(a). State two (2) physical properties of amide.
(b). How would you prepare ethanamide from an ester.
2(a). State two (2) chemical properties of amide.
(b). How would you identify an example of amine in the laboratory