Question

CH2-CH -CHO IUPAC name is

Answer 1

you can call it simply Butadiene, but its PIN (prefered IUPAC name) is Buta-1,3-diene. A breakdown of the name would show that

It has at least one double C-C bond (due to the -ene suffix)In actuality, it has 2 double bonds (-di)The carbon skeleton consists of 4 carbonsRegardless of the direction of numbering, 1,3 are the positions which are produced in the process.

Answer 2

Propionaldehyde is the IUPAC name