Law of mass conservation
This experiment tests the statement that during a chemical reaction the total mass of the system is conserved, even if chemical changes occur in the solution.
The science behind this experiment
What happens to the total mass of a system during a chemical reaction? Do chemicals change their weight during reactions? Lavoisier's law of mass conservation states that the mass of reactants is equal to the mass of products.
Equipment used
- Dropping pipette with teat — PLA-003+PLA-019
- 2 × Glass beakers 50 ml — CHE-002
- Spatula, double ended — PLA-024
- Electronic balance — CHE-015
Chemicals and reagents
- Silver nitrate 0.1 M — R:34-50/53 S:26-45-60-61
- Potassium iodide 0.1 M — R:42/43-36/37/38 S:26-38
Questions for students
- Describe what happens to the solution.
- What is the total weight of the two beakers plus the combined solution?
What to expect
When weighed again, it will be noted that the weight of the whole new system is equal to the weight of the initial system. This confirms that the total mass is conserved, even though a chemical reaction has occurred.
Disposal
Dispose of the solution into the acids and bases waste container.
Run this experiment in your classroom
This experiment is part of ATP Volta — a self-contained mobile science lab that turns an ordinary classroom into a working STEM laboratory, with over 200 experiments in physics, chemistry, biology, robotics and engineering. Gali, the AI tutor built into ATP Connect, guides students through each step and answers their questions at the bench.
See the ATP Volta mobile science labTalk to our team