These Q1-Q7 topic summaries are based on the official 2026 released FRQ PDF, but they avoid copying full prompts. The scoring notes are still unofficial until College Board publishes 2026 scoring guidelines.
Q1 / 10 points
KCl calorimetry, K+ atomic structure, enthalpy of solution, calorimeter error, and RbCl Ksp/common-ion reasoning.
High topic confidence confidence
Status: Official topic map; scoring notes unofficial. These notes identify scoring risks and answer-checking priorities; they are not official scoring guidelines.
Likely earns attention
- For K+ versus K, connect electron removal to fewer occupied energy levels and stronger effective attraction.
- For calorimetry, show q = mcΔT, use the total solution mass when appropriate, and convert J to kJ before molar enthalpy.
- For RbCl solubility, write the dissolution relationship, use Ksp, and explain common-ion effect from added chloride.
May still earn credit
- If your enthalpy sign is disputed, separate magnitude work from sign reasoning in your self-score.
- If your Ksp setup is right but the final arithmetic is wrong, count setup as a maybe-point until official scoring appears.
Watch for: Magnitude versus signed ΔH, solution mass versus water mass, endothermic temperature drop, saturated-solution assumptions, and common-ion explanation.
Q2 / 10 points
Chromate/dichromate structure, resonance, redox check, chromium electroplating, first-order kinetics, ln plot, and rate constant units.
High topic confidence confidence
Status: Official topic map; scoring notes unofficial. These notes identify scoring risks and answer-checking priorities; they are not official scoring guidelines.
Likely earns attention
- For VSEPR and resonance, preserve valence-electron count and formal-charge targets.
- For electroplating, connect current, time, moles of electrons, moles of Cr, and grams of chromium in one visible chain.
- For first-order kinetics, use concentration-versus-time evidence and the slope of ln concentration versus time.
May still earn credit
- A wrong final electroplating mass can still retain method points if charge and electron stoichiometry are clear.
- A correct slope magnitude with the wrong time unit should be treated as a disputed unit point.
Watch for: Formal charge distribution, deciding whether chromium oxidation number changes, ΔG sign from E°, Faraday stoichiometry, and min^-1 versus s^-1.
Q3 / 10 points
Nitrous acid equilibrium, pH to hydronium, Ka at different temperatures, titration curve reading, equivalence point, and indicator choice.
High topic confidence confidence
Status: Official topic map; scoring notes unofficial. These notes identify scoring risks and answer-checking priorities; they are not official scoring guidelines.
Likely earns attention
- For pH work, write [H3O+] = 10^-pH before calculating so the calculator step is visible.
- For Ka at a higher temperature, compare the new Ka with the given 298 K value before deciding endothermic or exothermic.
- For titration, read the equivalence point from the steep region and use stoichiometry from acid volume and NaOH molarity.
May still earn credit
- If your pH-to-concentration entry was wrong but the intended expression is written, count the setup separately from the final number.
- If your indicator conclusion is right but the justification does not mention the equivalence-point pH range, mark it disputed.
Watch for: 10^-pH calculator entry, weak-acid equilibrium subtraction, Ka temperature comparison, equivalence-point reading, and indicator transition range.
Q4 / 4 points
P4/P2 bond length, gas-phase equilibrium, Kp calculation, and thermodynamic favorability at high temperature.
High topic confidence confidence
Status: Official topic map; scoring notes unofficial. These notes identify scoring risks and answer-checking priorities; they are not official scoring guidelines.
Likely earns attention
- For bond length, connect shorter bonds to stronger or higher-order bonding rather than only molecule size.
- For Kp, use equilibrium partial pressures and the balanced relationship in the expression.
- For thermodynamic favorability, use ΔG = ΔH - TΔS reasoning rather than saying high temperature alone proves endothermic.
May still earn credit
- A correct high-temperature conclusion with incomplete entropy reasoning should be treated as a disputed justification point.
Watch for: Forgetting reaction coefficients in Kp, treating ΔG and ΔH as the same sign, and not mentioning entropy when the prompt asks for it.
Q5 / 4 points
CBrClF2 bond polarity, bond-angle differences, intermolecular forces, and boiling-point comparison.
High topic confidence confidence
Status: Official topic map; scoring notes unofficial. These notes identify scoring risks and answer-checking priorities; they are not official scoring guidelines.
Likely earns attention
- For most polar bond, compare electronegativity differences, not bond length or atom size alone.
- For bond angles, connect electron-domain repulsion and substituent differences to the observed angles.
- For boiling point, identify all relevant intermolecular forces before comparing relative strength.
May still earn credit
- A correct molecule choice with only one force named may still earn partial credit if the relative-strength argument is clear.
Watch for: Choosing polarity from atom size instead of electronegativity, ignoring molecular polarity, and saying heavier molecule without naming dispersion strength.
Q6 / 4 points
Spectrophotometry calibration, particle diagrams, dilution, concentration from absorbance, and volumetric-flask error.
High topic confidence confidence
Status: Official topic map; scoring notes unofficial. These notes identify scoring risks and answer-checking priorities; they are not official scoring guidelines.
Likely earns attention
- For particle diagrams, scale particle count with concentration or absorbance proportionally.
- For dilution, use M1V1 = M2V2 and clearly distinguish diluted and original solution.
- For volumetric-flask error, reason from final volume to diluted concentration to calculated original concentration.
May still earn credit
- If your graph-read concentration is close but not exact, keep the dilution setup separate in your self-score.
- If the conclusion about final volume is correct but the explanation skips the concentration link, mark it disputed.
Watch for: Reading beyond the calibration range, mixing up diluted versus undiluted concentration, and reversing the effect of overfilling the volumetric flask.
Q7 / 4 points
Na2O enthalpy of formation, limiting reactant heat release, and lattice enthalpy comparison using Coulomb's law.
High topic confidence confidence
Status: Official topic map; scoring notes unofficial. These notes identify scoring risks and answer-checking priorities; they are not official scoring guidelines.
Likely earns attention
- For ΔHf, use the balanced reaction and remember elements in standard states have zero formation enthalpy.
- For heat released, identify the limiting reactant before scaling the reaction enthalpy.
- For lattice enthalpy, compare ion size and distance using Coulomb's law.
May still earn credit
- A correct limiting-reactant setup with a coefficient error should be counted as a disputed stoichiometry point, not an automatic zero for all parts.
Watch for: Forgetting the coefficient on Na2O, scaling heat by the wrong reactant, confusing released heat sign with magnitude, and omitting ion-size reasoning.