Cleaning up his vomit? Eeewwwww no way!

Cleaning up beer cans in his room? Oh gees.....

With regards to the chores you and your brother are expected to do - I think there should be a clear understanding over who does what. Under normal circumstances I'd say 50/50 between the two of you, unless your mother thinks if he's working full time you can contribute more (you don't say if you're working full time too so not sure).