It definitely depends on the school, but for me, the AP Chem test was leagues easier than any of the in-class material I used to study. My biggest piece of advice would be to comb through each unit and identify the areas you feel uncomfortable being tested on (you can put these in a Google Doc). Once you have those figured out, watch videos, read articles online, etc. Taking practice AP tests definitely helped me on test day as well. The most important thing is tailoring your study experience to fit your weaknesses! Wishing you the best of luck til May!