See the answer below.
Work Step by Step
a) Yes, all of them have the molecular formula: $C_2H_4O$ b,c) The two carbons in ethylene oxide and the leftmost in acetaldehyde are $sp^3$ hybridized because they make 4 single bonds. Because of this, they have bond angles of 109°. The rest are $sp^2$ hybridized because they make a double bond each. Because of this, they have bond angles of 120°. d) All these molecules are polar because they have asymmetrical polar bonds. e) Vinyl alcohol's double bond is the strongest carbon-carbon bond. Acetaldehyde's double bond is the strongest carbon-oxygen bond.