How many positional isomers (Structural) exist for C₃H₅Cl₃

To determine how many positional isomers (structural isomers) exist for the compound with the molecular formula C3H5Cl3, let's break it down:

The molecular formula C3H5Cl3 means there are:

• 3 carbon (C) atoms
• 5 hydrogen (H) atoms
• 3 chlorine (Cl) atoms

Now, we need to identify the structural (positional) isomers of this compound. This means we will look at different ways the chlorine atoms can be positioned on the carbon chain.

Step-by-Step Breakdown:

1. Carbon Chain Structure:
   • The base chain is propane (C3H8) with 3 carbon atoms, but we have 3 chlorine atoms and 5 hydrogen atoms, so the structure will have chlorine atoms replacing some hydrogens.
2. Positional Isomers:
   The chlorine atoms can be attached to different positions on the carbon chain, which creates different isomers based on the positioning of chlorine atoms.

Possible Positional Isomers of C3H5Cl3:

1. 1,1,2-Trichloropropane:
   In this isomer, two chlorine atoms are attached to the first carbon and one chlorine atom is attached to the second carbon.
2. 1,1,3-Trichloropropane:
   Here, two chlorine atoms are attached to the first carbon and one chlorine atom is attached to the third carbon.
3. 1,2,2-Trichloropropane:
   In this isomer, one chlorine atom is attached to the first carbon, and two chlorine atoms are attached to the second carbon.
4. 1,2,3-Trichloropropane:
   In this isomer, one chlorine atom is attached to each of the first, second, and third carbon atoms.
5. 2,2,3-Trichloropropane:
   In this isomer, two chlorine atoms are attached to the second carbon and one chlorine atom is attached to the third carbon.

Conclusion:

There are 5 positional isomers (structural isomers) for the molecular formula C3H5Cl3.