The 2025-26 season CCO will be held on September 19, 2026. The specific dates for the 2026-27 season CCO are yet to be announced by the official organizers; the new cycle places greater emphasis on process scores and English argumentation.
I. CCO Scoring Trends and Competition Format Foundation
CCO is not a "harder version of CCC." It jumps from multiple choice to free response: writing derivations, writing designs, writing explanations.
| Dimension | CCC | CCO |
|---|---|---|
| Question Type | 25 multiple-choice questions | Usually 5 short-answer/proof questions, no hands-on experiments |
| Duration | 60 minutes | 120 minutes |
| Scoring Focus | Correct answer earns points | Steps, units, assumptions, and errors all count toward the score |
| Knowledge Level | Mainly high school chemistry | First-year university general chemistry, physical chemistry, and organic chemistry extensions |
| Language | English questions, focus on comprehension | English questions + English answers, focus on expression |
II. How to Break Through on Experimental Design Questions
CCO does not test "hands-on titration," but it often tests paper-based experiments: given an objective, write a procedure, calculate data, and explain errors.
Start with objectives and hypotheses: what to measure, what to compare, which chemical relationship to verify.
Then list variables: independent variable, dependent variable, and controlled variables—none can be missing.
Steps must be reproducible: reagent concentration, volume, temperature, and standing time must all be specified.
Prepare the data table in advance: column names with units, leave space for replicate samples, and don't just record "the result is roughly."
Analysis must connect to methods: how to calculate from standard curves, titration volumes, absorbance, and rate constants.
Errors last: systematic error/random error, instrument limitations, operational losses, and improvement plans.
Scoring Chain for Experimental Design Questions
| Section | What to Write | What Loses Points If Omitted |
|---|---|---|
| Hypothesis/Objective | One sentence clearly stating what is to be measured | Vague opening, like writing an essay |
| Variable Control | Which quantities remain constant | Temperature/concentration/volume mixed together |
| Procedure Steps | Order, amounts, instruments, safety | Vague phrases like "add an appropriate amount of reagent" |
| Data Processing | Formula + substitution + units + significant figures | Only writing the final number |
| Error Improvement | Source + direction + how to reduce | Writing useless statements like "the experiment has errors" |
III. How to Strengthen English Subjective Expression
Chemistry English is not about memorizing vocabulary; it is about writing "I thought correctly" into sentences that graders dare to give points for.
Use passive and objective sentences: The sample was dissolved in…, not I think it becomes…
Give the conclusion first, then the reason: Therefore… because… is more favored than lengthy buildup.
Use complete terminology: bond order, rate-determining step, ligand field—don't write half of it.
Follow formulas with text: write ΔG=ΔH−TΔS, and also explain what the symbols represent.
Do not drop units: writing mol L⁻¹, kJ mol⁻¹, nm, mL incorrectly is like missing a step.
Do not pile up long sentences: clear short sentences + connectives are more likely to earn process points than ornate subordinate clauses.
Chinese-English Expression Comparison
| Chinese Meaning | Recommended English Expression | Common Incorrect Writing |
|---|---|---|
| Control temperature | maintain the temperature at 75 °C | keep warm |
| Plot standard curve | plot a calibration curve of A vs concentration | draw a line |
| Rate-determining step | the rate-determining step limits the overall rate | slow step only |
| Source of error | a systematic error arises from… | maybe wrong |
IV. New Season Preparation Rhythm and Schedule
CCO preparation cannot wait for the invitation email; the language for long-answer questions and experimental logic should be practiced during the CCC stage.
After CCC: Award winners should immediately transition to CCO; those without awards should first reinforce high school chemistry before discussing advancement.
Summer: Go through the four major blocks—physical chemistry, organic chemistry, inorganic chemistry, and analytical chemistry—using university general chemistry textbooks.
8-10 weeks before the exam: One CCO past paper per week under timed conditions, correcting answers according to "steps + units + explanation."
Experimental question special training: Use old CCC Part B and CCO sample questions to practice "imaginary laboratory writing."
English expression: Build a terminology list and rewrite Chinese notes into English answer drafts.
Tiered goals: Aiming for Camp depends on Canadian qualifications and rankings; China region contestants should focus on the depth of academic materials.
CCO Season Preview Annual Checklist
| Time | Action |
|---|---|
| 2026-09-19 | 2025-26 CCO exam (120 minutes, 5 major questions) |
| Autumn 2026 – Spring 2027 | CCC foundation + CCO long-answer expression practiced simultaneously |
| 2027-04-21 | CCC China region exam; only award winners qualify for CCO invitation |
| From 2027-06 | CCC scores released; CCO advancement list expected to be published |
| Summer – Autumn 2027 | New CCO exam date pending announcement by CIC/ASDAN |
The new CCO trend is straightforward: it is not about who calculates fastest, but about who thinks through the chemistry clearly, writes it clearly, and explains the errors clearly.
