The 2024 SChL will be held online on 13 July 2024, from 9 am to 1 pm for a duration of 4 hours.

This competition is open to all JC/CI students or equivalent in Singapore. You are to form teams of 3-5 members to participate.

Each team is to answer correctly as many problems as possible, and as fast as possible. Every correct answer will earn your team points allocated to that problem (or part). Your total score will be updated in real-time on the competition leaderboard, where you may check your rank against other teams.

Your team will share one account on our competition platform, which may be accessed on all your teammates' devices simultaneously. Every action you make on the platform will be performed collectively for the whole team. This means only one team member is required to input answers to any problem. Do keep your account username and password safe!

You may:

  • Use any tools or reference materials to help you in the course of problem solving. This includes any legally accessible resources, such as scientific and graphing calculators, school notes, textbooks, online websites, videos, and computational software.
  • Discuss between members of the same team (either online or in-person) to facilitate your problem-solving process. This means that you can discuss and consult with your teammates through any form and at any location of your choice.

You must not:

  • Communicate in any form with members of a different team, including sharing materials or answers.
  • Spam the organising team with emails, discord messages, or any other form of communication. If you request our assistance, please send one message only and wait for our reply.
  • Perform any unsporting or unethical actions that unfairly advantages yourself or disadvantages other teams, including any intentional or unintentional attacks on SChL's web infrastructure.


There are three types of problems available: core, challenge and blitz problems. The examinable scope of the higher-order problems will be anchored in the International Chemistry Olympiad syllabus, and some may even explore advanced concepts beyond it.


Core Problems

The core problems can be attempted throughout the entire competition. They are presented in order of increasing difficulty, and either consist of a single part or multiple parts (which we will refer to as multi-part problems). Points for each part will vary, depending on the difficulty and expected solving duration.

Unlocking Problems

All teams begin the competition with a selection of eight core problems to unlock. At any point in time, each team can attempt a maximum of four core problems concurrently. You can unlock a new problem whenever your team is working on three or less problems, which happens at the start of the competition, or when you solve or skip a problem.

You have a limited choice on which new problem(s) to unlock. At any point in time, you can choose only between the next four problems that have yet to be unlocked, and you will only see their titles and allocated points, but not the topic or problem statement.

At the start of the competition, you have not unlocked any problems and have four empty slots to unlock problems.

Clicking on a problem slot will show you the option to unlock Problems 1, 2, 3, 4. Choose one to attempt.

Let us say you unlocked Problem 1 to attempt. Now you click on the next slot. This will show you the next four locked problems, giving you the options to unlock Problems 2, 3, 4, 5.

Supposing you unlock Problem 3 for this slot, you now have access to Problems 1 and 3. The next slot you select will give you the options to unlock Problems 2, 4, 5, 6.

Supposing you repeat this two more times and have access to Problems 1, 3, 4, 6. At this point, all your slots are filled with unanswered questions and you cannot unlock any more problems. You have to solve or skip a problem before freeing up a slot to unlock the next problem.

Suppose you solve Problem 1 successfully. You can now click on the slot which previously housed Problem 1 and will be given the option to unlock Problems 2, 5, 7, 8.

This unlocking process will continue until the competition duration ends or you unlock or solve all core problems. If you unlock and solve all core problems, you will not have any more core problems to unlock.

Point System

A correct answer yields the number of points alloted for that problem (if the problem has a single part) or that specific part (for a multi-part problem).

An incorrect answer has no penalty but decreases the obtainable points of the problem / part by 1 point, until it reaches 1. In other words,

Obtainable points = (Listed points - No. of incorrect attempts) OR 1, whichever is higher.

For example, for a 3-point problem, if you submit one incorrect answer, the points you can get decreases to 2. Another wrong answer and it decreases to 1. Subsequent wrong answers will not affect the obtainable points, which stays at 1. For such a problem, if you submit a correct answer after 2 or more tries, you get only one point.

An incorrect answer will also cause a cooldown period of 30 seconds, during which all team members would be unable to submit answers for that problem / part.

For multi-part problems, all individual parts will be available once you unlock the problem. You may attempt the parts in any order (i.e. you need not complete part (a) before attempting part (b)), and points are awarded individually for each part.

Skipping Questions

You may choose to skip a problem at any time. This makes the problem permanently unavailable. However, two points will be deducted directly from your total score. Skipping also causes a cooldown period of 10 minutes, during which you may not skip another problem.

For multi-part problems, choosing to skip that problem will mean skipping all its remaining unsolved parts.
(E.g. if you solve part (a) but choose to skip all the remaining parts, you will still be awarded points for part (a).)

The system will grant a “free skip” every 30 minutes from the start of the competition (meaning you have one right at the start). You may use free skips at any time to skip a problem without penalty. However, a 10-minute cooldown still applies during which you may not skip another problem. These free skips carry over, i.e. you need not use a free skip before 30 minutes is up, and are shared amongst the whole team.

For multi-part problems, choosing to skip that problem will mean skipping all its remaining unsolved parts. Two points will be deducted directly from your total score.


Challenge Problems - Catalytic Craze

The first special event, Catalytic Craze, will commence at the 1-hour mark, and will last 30 minutes.

During this event, teams will gain access to 1 challenge problem, which will remain visible even after the event has ended.

Teams will not be allowed to skip the challenge problem.

If the team solves a challenge problem within the duration of Catalytic Craze, they will be awarded double the points, for a maximum of 20 points. If they solve it outside the duration, they will be awarded a maximum of 10 points.


Blitz Problems - Atomic Rush

Atomic Rush will commence at the 2.5-hour mark, and will last 30 minutes.

During Atomic Rush, each team will be able to view 4 blitz problems at any time, on top of the core problems.

The key here is speed and accuracy. All blitz problems are worth one mark. Participants will have only one chance to answer a problem correctly, failing which the problem is automatically skipped with no time or score penalty, and the next unattempted blitz problem immediately made available (For example, you will view problems AR1-4 at the start. Once AR1 is solved, AR5 will be immediately unlocked.) Teams will not have a choice of which blitz problems they may attempt.

In addition, there will be the following score multipliers in place:

Score multiplierDescription
When a team solves 5 problems correctly in a row, the next problem attempted is worth x3 the points.
For each question that is solved within 2 minutes, that question will be awarded 2 points instead of 1.

The timer for Hyperbullet starts when anyone from your team first views the problem (i.e. accesses the problem pdf).

The score multipliers can stack; if both are in action, your next problem attempted is worth x6 the points. Each time a score multiplier is applied and its bonus awarded, the counter is reset for that score multiplier.

When a team solves 10 problems correctly in a row, the next problem attempted is worth x3 the points.

When a team solves a problem correctly within 1 minute of viewing the problem, the team will earn 2 points for that problem instead of 1 point.

The score multipliers can stack; if both are in action, your next problem attempted is worth 6 points.

At the end of Atomic Rush, both the blitz problems and the score multipliers will no longer be available.


Should you believe that a problem contains an error that makes it impossible to solve, or that an error has been made in the automated grading of your answers, please contact the organising team at [email protected], submit a ticket on the competition Discord server immediately. However, we will not entertain requests to explain certain terms, diagrams or concepts used.

Final Remarks

By registering and participating in SChL, you agree to abide by all of the aforementioned rules.

Leaderboards will only reflect team names, school(s) and not the individual names or emails. Personal data will not be publicly displayed on the website without prior consent.

Should we judge you to have broken any of the competition’s rules and/or have behaved in any manner dishonest or detrimental to the progress of the competition, we reserve the right to penalise and/or disqualify your team without prior warning, even if the behaviour is not explicitly prohibited in these rules.

After the competition, you may submit appeals on the grounds of any issues with the problems or solutions, or objections to penalties imposed by the organisers. If an appeal is accepted, we will update all scores and rankings accordingly.

All scores will be final and no further appeals will be entertained once the competition results are declared to be finalised.

If you have queries about any of the aforementioned material, do contact us at [email protected].