Step 1: Structure of isopentane

Isopentane is also called 2-methylbutane.
Its structure is:

2-Methylbutane (Isopentane)

       CH₃
        |
  CH₃ – CH – CH₂ – CH₃
       (C₂)
  

Structural representation (text). Central carbon (CH) bears the methyl branch → 2-methylbutane.

Step 2: Find different types of hydrogens

We check for unique positions where chlorine can replace hydrogen (monochlorination).

Type 1: Terminal CH3 (methyl) groups → 2 equivalent positions.

Type 2: Middle CH2 group → 1 unique position.

Type 3: The CH group (carbon with the branch) → 1 unique position.

Type 4: The branch CH3 group → 1 unique position.

So, there are 4 types of hydrogens.

Step 3: Possible monochloro derivatives

Chlorination can occur at any of these 4 types, giving 4 distinct isomers of monochlorinated isopentane.

Final Answer:

Total number of fractions obtained = 4