Kaplan's Chemistry does a great job of over-preparing you for the chemistry section of the exam. Apparently if you master Kap's Chem section, you're guaranteed a 90%tile in Chem. So, no, you you dont have to memorize henderson hassel bach, but you should know how to calculate pH/pOH. And at least other easy equations like Temperature conversions, Gibbs free energy -Goldfish are horrible without tarter sauce) or the pervert equation (gas Law equation) is another biggie. As you can see I love mnemonic devices

. But it is also important to know what each equation means, as there are many conceptual problems on the test (from what I've heard).