Conservation+of+Matter+Investigation

How might we prove the law of conservation of mass if one of the products is a gas?
 * Conservation of Matter/Mass Lab ** :

Copy and complete numbered items. 1. The law of conservation of matter/mass states that…….

Part 1: Open System a. Put 10mL of vinegar in an 80mL beaker. Measure and record its mass. b. Put a heaping plastic spoon full of baking soda in a 40mL beaker. Measure and record its mass. c. Place both beakers on a balance & record the starting mass. Take and record the temperature of the vinegar. d. Dump the baking soda into the 80mL beaker with the vinegar. (Do not stir) e. __Record all observations__ that indicate a chemical reaction has occurred. Also record the temperature of the mixture. f. Place both beakers on the balance & record the ending mass.

Part 2: Closed System a. Rinse out the 80mL beaker. Put 10mL of vinegar in an 80mL beaker. Measure and record its mass. b. Put a heaping plastic spoon full of baking soda into a plastic bag. Measure and record its mass. c. Without spilling any vinegar, put the 80mL beaker in the plastic bag. Try to push all the air out of the bag and seal it. d. Without spilling the vinegar, place it on a balance and record the starting mass. e. Without opening the bag, mix the vinegar and baking soda. Without opening the bag, record the ending mass. f. Rinse out the bag and 80ml beaker. Put the bag upside down over the beaker to dry on the back counter.

2. Calculate the amount of mass that changed in the open system by subtracting the ending mass from the beginning mass.

3. What percent did the mass change in the open system? Ending mass/starting mass X 100 = Percent change

4. Calculate the amount of mass that changed in the closed system by subtracting the ending mass from the beginning mass.

5. What percent did the mass change in the closed system? Ending mass/starting mass X 100 = Percent change

6. Why was it hard to prove the conservation of matter/mass when a gas is produced?

7. What is the difference between an “open” and “closed” system?

8. Copy the chemical equation for this reaction. Label the reactants and the products.

9. Count the number of atoms of each element on each side of the equation & record the total number.

10. A “balanced” reaction has the same numbers of atoms of each kind on both sides. Explain if this reaction is balanced or not.

11. Did this lab prove the law of conservation of matter/mass? Explain & use the data to support your answer.

12. What evidence of a chemical reaction was observed?