Answer: [tex]CH_3OCH_3[/tex] and [tex]C_2H_5OH[/tex]
Explanation: The compounds having similar molecular formula but different arrangement of atoms or groups in space are called isomers and the phenomenon is called as isomerism.
[tex]CH_3OCH_3[/tex] and [tex]C_2H_5OH[/tex] are functional isomers which have same molecular formula but different functional groups attached.
(1) [tex]NO_2[/tex] and [tex]N_2O_4[/tex] are different compounds.
(2) [tex]P_2O_5[/tex] and [tex]P_4O_{10}[/tex] are different compounds.
(3) [tex]HCOOH[/tex] and [tex]CH_3COOH[/tex] are different compounds.
