Suppose (C'mon, just suppose):

• I'm working on some changes for a project on Github (say, the Ruby project).
• I have an open PR for a single file (say, hash.c) in my branch hash.
• I have more changes, to a different file (say, array.c), in my branch array, and I'd like to put up a second PR for those changes.
• When I offer to create a second PR for array.c, its changes include those for hash.c.

So:

• Is it possible to create a second PR for array.c, without including the changes for hash.c?
• If so, would a subsequent merge of either PR "foul" the other, so that it couldn't be sensibly merged?

Thanks for any help.