AP Chemistry Full Mock Test 4

Emphasis: Equilibrium and Acid-Base Chemistry

Full Mock 4 weights Units 7 and 8 heavily — equilibrium, Ksp, Le Chatelier's principle, buffers, and titration curves. These units consistently produce the most complex FRQs on AP Chemistry exams, and Mock 4 is designed to give you concentrated, full-exam-context practice with this material.

Equilibrium Emphasis: What to Expect

ICE Table FRQs

Mock 4 includes multiple FRQ components requiring ICE table setup and solution. Some questions involve approximations (small K assumption); others require solving a full quadratic. Practise recognising when the 5% approximation is valid to save time under exam conditions.

Le Chatelier Reasoning Questions

Several items in Mock 4 describe a stress applied to an equilibrium system and ask you to predict the shift, identify which species change in concentration, and explain whether K changes. A complete response addresses all three elements — direction, species changes, and K vs. shift distinction.

Ksp and Precipitate Prediction

Mock 4 includes Ksp calculations — finding molar solubility from Ksp and predicting whether a precipitate forms when two solutions are mixed. The ion product comparison (Q vs. Ksp) is a common calculation in this exam section.

Acid-Base Emphasis: What to Expect

Buffer Calculation FRQs

Expect a long FRQ involving a buffer — calculating pH using Henderson-Hasselbalch, determining the effect of adding strong acid or base, and explaining the buffer mechanism at the molecular level. AP graders award separate points for the calculation and the explanation.

Titration Curve Analysis

Mock 4 includes a titration curve question where you must identify the equivalence point, explain why the equivalence point pH is above 7, identify the buffer region, and calculate pH at the half-equivalence point. Practise labelling all key features of both strong-strong and weak-strong titration curves.