In this activity students investigate the difference between closed and open systems and confirm, the Law of Conservation of Matter. They conduct and compare a chemical reaction taking place in a closed system with one occurring in an open system. They observe that while the mass of a gas-producing reaction decreases in an open system, it remains the same in a closed system. Their data is also used to reinforce the molecular nature of all matter, including gases.

• 1 Teacher's Guide with MSDS
• 28 Student Worksheets and Guides
• 12 Reaction bottles with screw-on dropper top
• 6 30 mL bottles of 4M HCl (half filled)
• 6 15 g vials of NaHCO3
• 6 White scoops

• To complete this kit requires one to two ~55-minute class periods
• Number of students: 24