NOMENCLATURE or NAMING OF ORGANIC COMPOUNDS

Q  A, B, C and D are four homologous series of organic compounds whose general formula can be represented as shown:

  a.  CnH2n+2

  b.  CnH2n

  c.  CnH2n+1OH

  d.  CnH2n+1CO2H

Name the homologous series represented by A,B AND C. Also, give the name and the structural formula of a typical member from series A and series B.

Ans

a.

(i)  CnH2n+2                 : Alkanes

 (ii)  CnH2n                   : Alkenes

 (iii) CnH2n+1OH         : Alcohols

 (iv)  CnH2n+1CO2H   : Carboxylic acids

b.

CnH2n+2 : General formula of the homologous series of alkanes

Example Methane (CH4):

              H         

                |          

H   ----    C   ----   H

                |      

               H

CnH2n : General formula of the homologous series of alkenes

Example Ethene (C2H4)

               H          H        

                |            |

               C   =     C 

                |            |

               H          H


Q. Name the family, then draw the compound.

Ans

(a) 2- pentanol


Family - alcohols.

(b) 2,4, 5 - trimethyl 3-heptanone


Famiy - ketones

(c) 2, 3 diethyl pentanal


Family - aldehydes

(d) propanamide


Family - amtoes

(e) propyl pentanoate


Family - Ester

(f) menthyl butyl pentyl amine


Family - amines


Q. Draw formulas for the following compound

(a) 3,4,5- tri methyl nonane

(b) 4 chloro - but-1-ene

(c) 3 - methy hexanal

(d) 3 bromopetanoic acid

(e) dimethyl ether

CH3 - O - CH3

(f) 1 - hexanol or hexan - 1- ol

(g) 2,3 dimethyl - 2- butanol

(h) propyl exhanoate


Q. Name the following compounds and tell what group they belong to:

(a)

Name: 5 - Ethyl -3, 3- dimethyl pentans
Group: Alkanes

(b)

Name: 2,3 - Dimethyl pentane
Group: Alkanes

(c)
Name: Bit -2 - yne
Group: Alkynes

(d)
Name: Methoxy elhane
Group: Ethers

(e)

Name: Butan -2 - ol
Group: Alcohols.

(f)

Name: Propanoic acid.
Group: Carboxylic acid.

(g)

CH3 - CH2 -NH2

Name: Ethanamine
Group: Amines

(h)

Name: Ethyl propanoate.
Group: Esters.

(i)

Name: propan -2 ol
Group: Alcohols.

(j)

Name: 2.3 - Dichloro butane
Group: Alkyl halides