How many isomers are there in the following:

Question

1. C2H4O (I was able to draw three.. Two involving a double bond and one involving a ring.)

2. C3H8O (I can only draw one..)

3. C2H4Cl (3 isomers?)

Answer 1

I can draw the three for 1.
For 2 I can draw two; i.e., 1-hydroxy propane and 2-hydroxy propane although those may not be proper IUPAC names.
For 3 I can draw any structure for C2H4Cl and certainly not three. I can draw for at least one structure for C2H5Cl, at least one for C2H3Cl and at least one for C2HCl.