About the DChO Chemistry Competition 2025 - National Mock
Who?
When?
When?
- Any high school student who is passionate about Chemistry and problem-solving.
- Recommended for USNCO 2025 National Exam qualifiers or 45+ in the Local 2025.
Completely free!
When?
When?
When?
- 8:30-10 PM ET on Mar 25 or 28 for Part I (MCQs).
Unfortunately, the Part II is NOT offered this year.
- Part I questions are explained at 8:30 PM ET on Apr 2 (Wed) over ZOOM.
How?
When?
How?
- Part I: Web-based (2nd camera needed for proctoring).
- mirror the intensity and rigor of the real USNCO Exams.
Gift cards for top participants!
DCC 2025 Award Winners
DCC 2025 Exam & Solutions
- by Dr. Chen and his team!
Detailed Info for DCC 2024-25 Winter Exam
Who?
When?
When?
- Any high school student who is passionate about Chemistry and problem-solving.
- Recommended for students preparing for the USNCO 2025 Local and National Exams.
- The Exams are free and open.
- The National Part II mock is invitation-only, based on performance in the Part I mock.
When?
When?
When?
- Level 2 Exam (mock Local): any consecutive 50 mins on Dec 16-22.
- Level 3 Exam (mock National Part I): any consecutive 50 mins on Dec 15-20.
- Level 4 Exam (mock National Part II): 7-8:30 PM ET on Dec 21 or 22.
- mirror the intensity and rigor of the real USNCO Exams.
How?
When?
How?
- Level 2 Exam: 24 Multiple-choice Questions.
- Level 3 Exam - Mock Part I: 24 Multiple-choice Questions.
- Level 4 Exam - Mock Part II: 6 Free-response Questions.
Topics covered in Winter Exam: Thermochemistry/Thermodynamics, Kinetics, Equilibrium, Redox/Electrochemistry (not covered in Level 2 Exam).
Detailed Info for DCC 2024-25 Fall Exam
Who?
When?
When?
- Any high school student who is passionate about Chemistry and problem-solving.
- Recommended for students who are preparing for the USNCO 2025 Local and National Exams.
- The Exams are free and open (you don't need to take Dr. Chen's classes to take the exam).
When?
When?
When?
- Level 2 Exam (mock Local): any consecutive 40 mins on Oct 12-13.
- Level 3 Exam (mock National Part I): any consecutive 40 mins on Oct 12-13.
- mirror the intensity and rigor of the real USNCO Exams.
How?
When?
How?
- Level 2 Exam: 24 Multiple-choice Questions.
- Level 3 Exam: 24 Multiple-choice Questions.
Topics covered in Fall Exam: Stoichiometry/Solutions, IMFs/States of Matter, Atomic Structures/Periodicity, Molecular Structures/Bonding.
DCC 2024-25 Fall Exam & Solutions - Level 2&3
Note: Q23 in Level 3 was replaced in the annotations.
DChO Chemistry Competition 2024 concluded with thrilling results!
DCC 2024 Exam & Solutions
- by Dr. Chen and his team!
DCC 2024 Award Winners
DCC 2024 Part I Exam - Score Distribution
About the DChO Chemistry Competition (DCC) 2024
Who?
When?
When?
- Any high school student who is passionate about Chemistry and problem-solving.
- Recommended for USNCO 2024 National Exam qualifiers or 45+ in the Local 2024.
When?
When?
When?
- Any consecutive 90 mins on Mar 25-31 for Part I (MCQs).
- Designated consecutive 105 mins on Apr 1-5 for Part II (FRQs).
- Part I questions are explained at 8:30 PM EST on Apr 6 over ZOOM.
How?
When?
How?
- Part I: Web-based.
- Part II: Paper-based, the top 10 or 20% participants in Part I are invited to take Part II, graded by Dr. Chen and his team.
- mirror the intensity and rigor of the real USNCO Exams.
Awards for DCC 2024
Logistics
Logistics
Logistics
- A formula of Part I×1.25 + Part II is used to determine the award winners.
- The graded Part II paper will be provided to all invited participants.
- The Part I & Part II exam paper will be posted on the https://dcho.us website after the each test period.
Awards
Logistics
Logistics
- Gold Award: $125 discount for Dr. Chen's Advanced National Prep Class or $100 gift card.
- Silver Award: $80 discount or $60 gift card.
- Bronze Award: $50 discount or $30 gift card.
Note: the number of each award is determined by the total number of participants.
Ceremony
Logistics
Ceremony
- The award winners will be announced at the end of the Part I explanation session on Apr 6.
- The detailed results [with personal info removed] and stats will be posted on the https://dcho.us website afterward.
- A brief written explanation of Part I may be provided later.
Interested in Chemistry Olympiad Classes for 25–26?
Choose the path that fits you best:
- Self-Study + Diagnostic
Study Honors or AP Chemistry on your own, then take Dr. Chen’s diagnostic tests to determine fall placement. Recommended textbooks - Summer Class with Dr. Chen
Take an intensive AP Chemistry+ or Organic Chemistry Class this summer with Dr. Chen to prepare for Level 2, 3, or 4 Olympiad training in the fall. - Start Now – Self-Paced
Prefer to begin right away? Purchase recordings and materials for Level 2, 3, or 4 from 2024-25 and start learning at your own pace!