A compound is formed by the substitution of two chlorine atoms for two hydrogen atoms in propane. What is the number of structural isomers possible ?

Explanation

To determine the number of structural isomers formed by the substitution of two chlorine atoms for two hydrogen atoms in propane, we can follow these steps:

### Step 1: Understand the Structure of Propane
Propane (C₃H₈) has the following structure:
- CH₃-CH₂-CH₃

### Step 2: Identify the Substitution
In this case, we are substituting two hydrogen atoms with two chlorine atoms. This can occur in different positions on the propane molecule.
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