what is the acceptable name for CH3CH2-O-CH2CH2CH2CH3?

Most of us would call it n-butyl ethyl ether. You can also call it 1-ethoxybutane.

ethyl n-butyl ether (common name)

1-ethoxybutane (IUPAC name)

I'm certain that the IUPAC bean-counters would insist on "official nomenclature". However, given either of the foregoing compound names an organic chemist would be able to draw a single structure. Both names describe the same structure.

You can find software online that permits you to draw a chemical structure and then provides the IUPAC name for the structure that you have drawn.

Since this is my first post, I am forbidden by Biology-Forums Powers-That-Be to post a link. In order to circumvent this restriction l suggest that you use "chemdoodle" as your Google online search term, which should lead you to chemdoodle's "demos/iupac-naming" webpage.

If you see this message, then my subterfuge must have been successful. We live in hope.

Hope this helps.

Thank-you!
Can you identify what the functional group is for CH3CH2-O-CH2CH2CH2CH3?

Yep. Perhaps not surprisingly, ethyl n-butyl ether contains an ether (R-O-R') functional group.

Do you mean its common name in the market place? Its ethyl n-butyl ether