AP Chemistry Tutoring

AP Chemistry is the College Board course built to match a first-year college chemistry class. It moves fast, and it asks for more than correct answers. On the exam you calculate, but you also explain, using particle-level reasoning and evidence from data, graphs, and lab setups. Students who can solve a problem at home still lose points when a question says to justify. STEM Tutor 360 offers one-on-one AP Chemistry tutoring that covers both halves: the calculations and the written reasoning.

Sessions run alongside your class during the school year, one unit at a time, then shift to cumulative review as the exam gets closer. Bring your unit tests, problem sets, and any released free-response questions you are practicing. Your tutor checks your written answers against the published scoring guidelines, points out where a statement is too vague to earn credit, and helps you rewrite it in specific terms.

A typical AP Chemistry problem, worked

A rigid 5.00 L tank at 27°C holds 0.200 mol of $\ce{N2}$ and 0.0500 mol of $\ce{O2}$. Find the total pressure and the partial pressure of $\ce{O2}$. Then predict what happens to the pressure at 127°C, and justify your answer.

Convert to kelvins with $\text{K} = {}^\circ\text{C} + 273$, so $T = 300\ \text{K}$. The total is 0.250 mol, so $$P = \dfrac{nRT}{V} = \dfrac{(0.250\ \text{mol})(0.08206\ \text{L atm/(mol K)})(300\ \text{K})}{5.00\ \text{L}} = 1.23\ \text{atm}$$ Oxygen is $\dfrac{0.0500}{0.250} = 0.200$ of the moles, so its partial pressure is $0.200 \times 1.23\ \text{atm} = 0.246\ \text{atm}$.

At 127°C the temperature is 400 K. The moles and volume have not changed, so pressure scales with temperature: $1.23\ \text{atm} \times \left(\dfrac{400\ \text{K}}{300\ \text{K}}\right) = 1.64\ \text{atm}$. The justification is what earns the point. A higher temperature means a higher average kinetic energy, so the particles move faster and strike the walls more often and with more force. The amount of gas and the volume are the same, so the pressure rises.

The exam and the nine units

College Board organizes the course into nine units, listed below. The exam has a multiple-choice section and a free-response section, and scores are reported from 1 to 5. The current course and exam description lists question counts, timing, unit weights, and the rules on calculators and reference sheets, so check it for the details that apply to your year.

• Unit 1: Atomic structure and properties
• Unit 2: Molecular and ionic compound structure and properties
• Unit 3: Intermolecular forces and properties
• Unit 4: Chemical reactions
• Unit 5: Kinetics
• Unit 6: Thermodynamics
• Unit 7: Equilibrium
• Unit 8: Acids and bases
• Unit 9: Applications of thermodynamics

How we build your plan

• Start with a diagnostic: your latest unit test or a released exam section, sorted by unit.
• Pair each class unit with problems in the exam's style, including data analysis and particle diagrams.
• Practice written answers that make a claim, cite evidence, and tie it to a model. Then compare them with the published scoring guidelines.
• Add timed multiple-choice sets later in the year to build pacing.
• Keep an error log. Each miss gets a note on the idea behind it, and we revisit the list before the exam.