Answer: Structural formulas for these esters HCOOCH2CH3 and CH3COOCH3.
Explanation:
An ester is to react an acid with an alcohol. For ethyl formate, you would need to react formic acid with ethanol.
HCOOH + CH3CH2OH -> HCOOCH2CH3
Methyl ethanoate, you would react ethanoic acid (acetic acid) with methanol
CH3COOH + CH3OH -> CH3COOCH3