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10 Science
Conservation
of
Mass Lab
Name:_____________________
Problem: Is mass conserved when a chemical reaction takes place?
Hypothesis:____________________________________________________
_____________________________________________________________
Materials:
conical flask
small test tube
#6 rubber stopper
solutions of lead nitrate and potassium iodide
triple beam balance
Procedure: As outlined in class
Observations:
Qualitative and
mass of empty flask, test tube and stopper
mass of flask, test tube, stopper and solutions before reaction
mass of flask, test tube, stopper and solutions after reaction
_________
_________
_________
Questions;
1. How do you know that a chemical change took place?
2. Write a word equation for the reaction that took place.
3. Which product has a property that allows us to see that a reaction took
place?
4. What is the property of the product identified in question #3?
5. Compare the total mass of the reactants with the total mass of the
products.
6. The Law of Conservation of Mass states that the total mass of the
products in a chemical reaction is equal to the total mass of the
reactants. Do your results support the law? Explain.
7. When magnesium metal is heated a white ash forms and the mass
increases. Account for these observations which apparently violate
the Law of Conservation of Mass.
Conclusion: