`H-CHO overset("1) "RM_(g)X," ether")underset("2) "H_(2)O)rarrX overset(+R'-COOH)underset(H^(+))rarr Y`.
What are the structures of X and Y? 

Explanation

`HCHO overset("1) "RM_(g)X)underset("2) "H_(2)O)rarr underset(X)(R-CH_(2)OH)overset(+R.-COOH)underset(H^(+))rarr R^(1)-underset(Y)(COOCH_(2)R)`
Aldehydes on treatment with `R-Mg-x 1^(@)` alcohol is obtained.
`1^(@)` alcohol on treatment with an acid will from ester in presence of `H^(+)` reaction is known as esterification reaction.