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 ?

A compound is formed by the substitution of two chlorine atoms for two

1.	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 ?
Answer» SOLUTION :Four : 1, 1-dichloropropane `(CH_(3)CH_(2)CHCl_(2))`, 1, 2-dichloropropane `(CH_(3)CHClCH_(2)Cl)` , 2,2-dichloropropane `(CH_(3)C Cl_(2)CH_(3))` and 1, 3-dichloropropane `(ClCH_(2)CH_(2)CH_(2)Cl)`.