Conservation of Mass Lab Pt 3

Conservation of Mass Lab—Part 3: Alka Seltzer & Water

Objective: You will observe and measure the reaction between Alka Seltzer and water on a scale to compare to your reactions from yesterday .

1. Make a hypothesis: Explain what you will happen when the Alka Seltzer is placed in the water while it is on the scale.

Procedure:

1. Fill your plastic cup half filled with water

2. Place the water cup and the Alka Seltzer tablet on the scale. 

3. Record the mass in your data table.

4. Place the Alka Seltzer in the cup and observe for mass and signs of chemical reactions.

5. When the reaction is finished record the new mass in the data table.

Data table:

Mass of Alka Seltzer and water before: (g)	Mass after reaction: (g)	Difference in mass: (g)

Analysis:

1. The antacid in Alka-Seltzer is sodium bicarbonate (NaHCO₃). It decomposes to form CO₂ and NaOH. Write a balanced equation for the decomposition of the sodium bicarbonate.

2. How many grams of CO₂ were put into the air in the reaction? Convert these grams to moles.

3. Calculate how many molecules of CO₂ were added to the room?

4. Does this reaction “break” the law of conservation of mass? Explain why or why not.