"Here is butter for the rice."
Translation:Вот масло для риса.
Because "для" means "for (the benefit of)", and "за" usually means "behind" (unless you exchange things, for instance).
I've found that за only means for in cases like Thanks for that, I am responsible for you.
Обед: Nominative and accusative case forms for masculine singular Russian word meaning "lunch" or "middle meal" = "dinner" (but at a time which would be deemed in American English to be a very early, possibly even a late lunch, or as in traditional Sunday dinner, served in early afternoon. Apparently not the evening meal understood by most American English speakers.)
обеда: Genitive singular case form of обед.
обедь: I can't find this word anywhere. Where did you get it? It's not the verb обедать/пообедать.
Which would be more common, для риса or к рису? Is there a difference in meaning or connotation?
I have forgotten most of the rules for genitive case and would like to know why it is in this case.