The isomerism exhibited by n- propyl alcohol and isopropyl alcohol is 

Concept:

Isomers:

• These are the compounds that have the same molecular formula but different structures or stereochemistries.
• There is a wide range of classification of organic molecules based on their structures.

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• Metamerism: When isomers have the same molecular formula but differ in nature of alkyl groups attached to it.

• A class of compounds that have the same molecular formula but can have different functional groups exhibit functional isomerism.

• Positional isomers: Isomers having different positions of their functional groups.

(iii) C₃H₇Cl represents two position isomers

• Optical isomerism:

  • When two isomers rotate plane polarised light in different directions, then they are known as optical isomers.
  • The phenomenon is known as optical isomerism.

Explanation:

• The molecular formula of propyl alcohol is C₃H₈O.
• In the positional isomers, these things might differ:
  • The position of the substituent.
  • The position of the functional group.
  • Arrangement of carbon atoms in the chain.
• The structure of  n- propyl alcohol and isopropyl alcohol are:

• It is clearly seen that in n-propyl alcohol, the functional group -OH is in position 1 whereas in isopropyl alcohol it is in position two.

Hence, they are positional isomers.