The number of isomers that C3H6Cl2 can have depends on the possible arrangements of the atoms in the molecule. First, let's consider the number of possible structural isomers that can be formed. Structural isomers are molecules with the same molecular formula but with different arrangements of their atoms. For C3H6Cl2, there are two possible structural isomers: 1,1-dichloropropane and 2,2-dichloropropane. Next, we can consider the possibility of stereoisomers, which are molecules with the same molecular formula and the same structural arrangement of atoms, but with different orientations of atoms in space. However, in C3H6Cl2, there are no chiral centers (carbon atoms with four different substituents), so there are no possible stereoisomers. Therefore, the total number of isomers for C3H6Cl2 is 2