To do well in the class, you need to have already taken an introductory Chemistry course. At the pace this class moves, there is no way you could keep your head above water without a solid foundation. You can read about the course on the College Board website here. Like AP Biology, AP Chemistry requires that 25% of instruction time be spent doing experiments. So you’ll have to master the Laws of Thermodynamics, molecular bonds, and chemical properties pretty quickly, and then know how to apply them.
To keep up with all these concepts, teachers tend to assign lots of homework so they make sure students are absorbing and retaining the material. AP Chemistry is also notorious for long and difficult tests throughout the year.
To do well in the course, you’ll need a solid study schedule and be willing to set aside at least an hour or two a day after school to review.
Taken from https://www.albert.io/blog/what-are-the-hardest-ap-classes/