Question

Compounds which are isomeric with diethyl ether

Answer 1

It was originally used to apply to compounds that had the same ratios of atoms, but in different arrangements. Thus, methyl propyl ether and diethyl ether are indeed isomers of each other. There are actually two isomers of methyl propyl ether, which are methyl n-propyl ether and isopropyl methyl ether.