I indeed have took AP Chem and SAT Subject Chem.
Thinking that SAT II should not be too hard, I didn't study for SAT II. I just studied using PR
AP chem book. Guess what, I got a 690.
I read through Barron's SAT II Chem book once or twice and managed to get a 770 the second time (I should've got 800. My proctor did not manage the time correctly)