Proton transfer. Bronsted-Lowry acids and bases, pH and pOH of strong and weak acids/bases, molecular structure and acid strength, acid-base reactions and titrations, and the properties of buffers.
Six ways to master Unit 8 — pick whichever fits how you like to study.
Nine topics from the College Board CED, in order.
Unit 8 takes the equilibrium tools from Unit 7 and applies them specifically to proton-transfer reactions. You'll learn to calculate pH and pOH for strong acids and bases (which dissociate completely) and for weak acids and bases (which require an equilibrium calculation using Ka or Kb). You'll connect molecular structure — bond polarity, atomic size, electronegativity — to relative acid and base strength, read titration curves to extract pKa and equivalence point information, and understand how buffers resist pH change using the Henderson-Hasselbalch equation.
This unit is roughly 11–15% of the AP Chem exam — the second-highest weighted unit after Unit 3 — and takes about 22–24 class periods. Every equilibrium skill from Unit 7 (Q vs. K, ICE tables, Le Châtelier's principle) returns here in the specific context of acids and bases.
The College Board ties Unit 8 to two core Big Ideas: