isomer

Asked by divi | 24th Feb, 2020, 05:12: PM

Expert Answer:

The existance of a molecule in different structural forms all having the same molecular formula is called isomerism.
Types -
 
1. Chain isomerism - If the length of the isomeric forms varies it is called chain isomerism. they can be either straight chain or branched chaains.
eg. Molecular formula having C4H10 is called butane they can have normal straight chain and a branched (iso) form.

Butane has two structural isomers.
 
  n- butane

2. Functional isomerism - if same molecuar formula can have different types of functional group.
Eg - Ethanol (C2H5OH) have -OH as functional group whereas ethers have -O- as functional group but both have same MF as C2H6O.
 
3. Metamerism - If there is shifting of 1CH3 group in case of ethers it is metamerism.
eg - CH3-CH2-O-CH2-CH2-CH3  & CH3-O-CH2-CH2-CH2-CH3 both have same MF.
 
4. Positional isomers - If the position of the functional group changes in a molecule it is positional isomerism
Eg - ClCH2CH2CH2CH3 & CH3CH(Cl)CH2CH3
 
5. Geometrical Isomerism - If the relative positions of the priority groups are same or different with respect to the double bond it can either be cis form or trans form.
Eg - Cis-Butene and Trans-butene
 
 
6. Stereoisomerism - Also called space isomerism depends on the rotation of a molecule in a polarimeter.
 
7. Tautomerism - Resonance between sigma and pie bonds like formation of enol from aldehydes.

Answered by Ramandeep | 24th Feb, 2020, 05:59: PM