The first Northeastern student/graduate I ever met is currently working at Merck, a chemical research lab in the Boston area. It was their second co-op, and they had an offer on graduation. Many will work in other research labs in Boston and around. Pay is decent, ranging of course. There are some higher ones and lower ones.
Co-ops generally are plentiful in Boston but also other major cities such as San Fransico, Seattle, New York, DC, LA, and Philadelphia. Northeastern has co-op housing in many of those listed. Again, I can’t speak exactly to Chemical Engineering, but perhaps someone else can!
Edit: I just realized I shared the exact same story in a previous post in this thread way back - oops! lol.
I really can’t give an exact range with certainty, but guessing based on experience, $15-$25 an hour would be my estimate.