Question

The compound which is not isomeric with diethyl ether is ________.
(A)- Butanone
(B)- Methyl propyl ether
(C)- 2-methyl propane-2-ol
(D)- Butanol-1

Answer 1

Isomers are those compounds which have the same molecular formula but have different structural formulas. So, the compound among the above given compounds is not isomeric with diethyl ether whose molecular formula is not the same as diethyl ether.

Complete answer:
Here is the detailed explanation of above all given compounds:
-Molecular formula of diethyl ether is ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{O}}$and structurally it is shown as ${\text{C}}{{\text{H}}_{\text{3}}}{\text{ - C}}{{\text{H}}_{\text{2}}}{\text{ - O - C}}{{\text{H}}_{\text{2}}}{\text{ - C}}{{\text{H}}_{\text{3}}}$.
-In option (A) Butanone is given, structurally which is shown as ${\text{C}}{{\text{H}}_{\text{3}}}{\text{ - C}}{{\text{H}}_{\text{2}}}{\text{ - CO - C}}{{\text{H}}_{\text{3}}}$. Its molecular formula is ${{\text{C}}_{\text{4}}}{{\text{H}}_8}{\text{O}}$which is totally different from the molecular formula of diethyl ether i.e. ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{O}}$. So, butanone is not isomeric with diethyl ether.
-In option (B) Methyl propyl ether is given, structurally which is shown as ${\text{C}}{{\text{H}}_{\text{3}}}{\text{ - O - C}}{{\text{H}}_{\text{2}}}{\text{ - C}}{{\text{H}}_{\text{2}}}{\text{ - C}}{{\text{H}}_{\text{3}}}$. Its molecular formula is ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{O}}$which is same as the molecular formula of diethyl ether i.e. ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{O}}$. So, Methyl propyl ether is isomeric with diethyl ether.
-In option (C) 2-methyl propane-2-ol is given, structurally which is shown as ${\text{C}}{{\text{H}}_{\text{3}}}{\text{ - C}}\left( {{\text{C}}{{\text{H}}_{\text{3}}}} \right)\left( {{\text{OH}}} \right){\text{ - C}}{{\text{H}}_{\text{3}}}$. Its molecular formula is ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{O}}$which is same as the molecular formula of diethyl ether i.e. ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{O}}$. So, Methyl propyl ether is isomeric with diethyl ether.
-In option (d) Butanol-1 is given, structurally which is shown as ${\text{C}}{{\text{H}}_{\text{3}}}{\text{ - C}}{{\text{H}}_{\text{2}}}{\text{ - C}}{{\text{H}}_{\text{2}}}{\text{ - C}}{{\text{H}}_{\text{2}}}{\text{ - OH}}$. Its molecular formula is ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{O}}$which is same as the molecular formula of diethyl ether i.e. ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}{\text{O}}$. So, Methyl propyl ether is isomeric with diethyl ether.

Hence, option (A) is correct.

Note:
During the formation of structure some of you may get confused between the ketone functional group and alcohol functional group, because Butanone & Butanol sounds similar. So, pay attention at this point during forming the structure.