"The molecular formula of A is" `C_(2)H_(4)O_(2)` ."Sicne this compound is acidic in nature it should contain carboxylic acid group",-COOH. "If we subtract COOH group (1 carbon , 2 oxygen and 1 hydrogen atom) from" `C_(23)H_(4)O_(2)`, "we are left with 1 carbon atom and 3 hydrogen atoms which is a methyl group" , `CH_(3)` "combining" `CH_(3)` "and" COOH "we get" `CH_(3)COOH`. "Thus, compound A is ethanoic acid" `CH_(3)COOH` . "When ethanoic acid is warmed with ethanol in the presencve of conc". `H_(2)SO_(4)` a pleasant and fruity smelling ester, ethyl ethanoate is formed .(write the equation yourself).