The chemistry lab puzzle in the abandoned school section (Part 2) of Sarab on Roblox requires players to gather four specific chemical solutions, inspect the chalkboard for the session's designated sequence, and pour each substance onto its corresponding table. Because playthroughs confirm that the exact order listed on the chalkboard can vary between runs, solving the puzzle depends on matching each chemical's visual effect to the environmental trace on the table. Once all four are poured in the correct order, the lab drawer unlocks to grant the Principal's Key.
How the Chemistry Lab Puzzle Works
Inside the chemistry lab at Hassoun Al-Barqi Secondary School, you will find four distinct testing stations. Each station bears a physical trace left behind by previous experiments. The chalkboard in the lab lists the required order (numbered 1 through 4) for your specific game session.
| Table Trace | Required Chemical Solution | Liquid Color / Property |
|---|---|---|
| Burnt Table Surface | Fire / Corrosive Substance | Orange |
| Rusted Table / Fixture | Rust Remover | Brown |
| Clean Table Surface | Freezing Agent | Blue |
| Stained / Toxic Spot | Poison / Toxic Substance | Green |
Do not pour randomly. Pouring an incorrect substance or pouring out of the order written on the chalkboard triggers an explosion or fails to open the drawer.
Where to Find All Four Chemical Substances
Before you can interact with the lab tables, you must explore the school halls to find the keys, complete mini-challenges, and collect all four chemical bottles.
1. The Classroom Exam
Head to the active classroom when the school bell announces the test. Sit at a student desk to begin the multiple-choice exam. The questions cover general trivia (such as the camel being the ship of the desert, Egypt being home to the pyramids, and basic logic questions about family names). Selecting the correct answers and submitting the test paper grants you a classroom key needed to progress.
2. The Flooded Restroom Valves
In the upper-floor restrooms, you will enter a flooded maze area accompanied by an audio warning regarding water conservation. To drain the water and retrieve the blue freezing solution:
- Navigate the submerged corridors.
- Locate and interact with all four leaking water valves or faucets to shut them off.
- Once all four water sources are closed, the flood level recedes, allowing you to pick up the blue beaker at the end of the corridor.
3. The UV Briefcase Code
In classroom 1-4, you will encounter a locked briefcase requiring a three-digit code.
- Switch your flashlight from standard white light to the purple ultraviolet (UV) beam by pressing your flashlight toggle key (default R or F depending on your platform controls).
- Shine the UV beam across the room to reveal hidden numbers painted on specific pieces of furniture: the student desk/table, the window, and the chair.
- Enter the revealed digits in the order indicated by the clue (Table, Window, Chair).
- Unlocking the briefcase yields the orange heat/fire chemical.
4. The Hallway Projectile Classroom
On the third floor, you will enter a classroom where a hostile shadow entity throws books and furniture at you. Crouch or sprint between the rows of desks, using them as physical cover each time an object is thrown. Advance table by table until you reach the far back of the room to claim the remaining chemical substance.
Step-by-Step Chemistry Lab Solution
- Collect all four flasks: Ensure your inventory contains the orange (fire), brown (rust remover), blue (freezing), and green (toxic) solutions.
- Return to the Chemistry Lab: Enter the lab and walk up to the chalkboard at the front of the room.
- Check the board sequence: Read the numbers 1, 2, 3, and 4 displayed on the board. Note which trace or icon is assigned to each position. For example, one run may demand Burnt (1) → Toxic (2) → Clean (3) → Rusted (4), while another run may list Rusted (1) → Clean (2) → Burnt (3) → Toxic (4).
- Interact with the tables in order:
- Locate the table matching position 1 and interact with it to pour the matching chemical.
- Proceed to table 2, table 3, and table 4 in exact order.
- Collect the Principal's Key: After pouring the fourth substance correctly, the chemistry desk drawer will slide open. Pick up the golden Principal's Key inside.
What to Do After the Lab Puzzle
With the Principal's Key in hand, head downstairs to unlock the Principal's Office. Inside, you will uncover audio recordings and notes revealing the backstory between Mr. Nasser and Mr. Abdullah. You will also find a file containing Abu Noura's address: Building 1431, Apartment 7.
Exit the school grounds and return to your vehicle to begin Part 3 of Sarab.
Frequently Asked Questions
Why did the chemical experiment explode?
The experiment explodes or resets if you pour a chemical onto a table that does not match its physical trace, or if you pour onto the tables out of the order written on the lab's chalkboard. Always verify the numbered board in your current session before pouring.
Does the chemistry puzzle order change every match?
Yes. Video playthroughs demonstrate that different sessions generate different sequence orders on the chalkboard. Inspect the board in your own lobby rather than following a static numerical sequence from an outside video.
How do I switch to the purple flashlight in the school?
Press the UV toggle button (R on keyboard by default; on some setups, press F to turn the flashlight on/off and R to switch to the ultraviolet filter). The purple light is required both to read the hidden briefcase numbers and to ward off the spirit stalking the school corridors.
