How many isomers can a formula of #C_3H_5Cl_3# generate?
these are the possible structures
I think I can count 5 structural isomers.
All these names (I think) are unique, which is a good indication that they are distinct compounds. Again, this is a good demonstration of the richness of carbon chemistry: a saturated carbon chain with 3 carbon atoms, with only 3 of the same heteroatoms, and yet (at least!) 5 structural isomers. How can organic chemists make anything unique?