a. The skeletal structure of the compound is shown below:

Structure of N-methyl ethanamide
The corner represents a carbon atom, and the bonding between carbon and the heteroatoms is shown in the structure. The hydrogen atoms are assumed to be present at each carbon.
b. The skeletal structure of is shown below:

The structure of 1-bromopropanone
c. The skeletal structure ofis shown below:

The structure of 2-methyl-2-propanol
d. The skeletal structure of is shown below:

The structure of acetyl chloride
e. The skeletal structure of is shown below:

The structure of 3-oxo-butanoic acid
f. The skeletal structure of is shown below:

The structure of 2-hydroxy-1,3 -dipropanoic acid