To start, for chem 121 I know a lot of my friends took it with Professor Ling Chen and really loved her. Likewise, I took it with Dr. Pasternak, and thought he was excellent (also, very easy / friendly / forgiving!!). I highly recommend him
Not sure how much you do / do not already know about the program -- hope this is helpful and not something you already know! But if you haven't already done it go have a talk with Mr. Sierra who is the pre-nursing advisor. Program entry is determined by some pretty wacky criteria, and if you're not aware of them going in it can make it really hard to get in! Basically all they do is take your GPA from four "core" classes (english 1, dosage calculations, anatomy 1, and psychology), and use that GPA to rank you against all the other's trying to get in -- they only go to your overall GPA in a tie. The cutoff GPA is different each time but generally it's in the 3.8 ballpark.
So basically even if you have a terrible GPA (or a really good one) it's irrelevant - as long as you pull down 4 A's in those classes you're golden. A friend of mine made the mistake of transferring in a B+ for english (b/c no one told him these rules), got A's in the other 3 classes, and ended up just getting in to the program pretty much right at the cutoff GPA for his year.
Finally, if you've already got a bachelors and plan on attending full time (without working concurrently) I think its worth looking into the accelerated bachelors programs at schools
like columbia or pace, since they only take a year. At least with my own situation being out there earning a salary a year+ earlier (with a bachelors in nursing to boot) more than offsets the total cost of the private school programs, although if you're working part time / full time while at BMCC this wouldn't hold true.
Anyway, hope this helped and good luck next semester!