1. Conservation of Matter

2. The Work of Lavoisier
Follow along as I read through the paragraph carefully. Circle any word that you don’t understand.

3. The Work of Lavoisier Read through the paragraph again.
What do you think are the key terms or words that help you better understand what Lavoisier (the author) is trying to explain?

4. The Work of Lavoisier
Read through the paragraph again focusing on the key terms/words we identified.
In one sentence, summarize what Lavoisier is trying to explain.

5. What Trend Did You Notice in the Data of the 5 Experiments?

6. Matter Matter: anything that has mass and takes up space.
Mass: a measure of the amount of matter in a substance.
Units are grams (g)
So…
If mass is conserved, so is matter.

7. Law of Conservation of Matter
With your table mate, discuss your own definition for the Law of Conservation of Matter based on what you learned in the experiments.

8. Law of Conservation of Matter
In a closed system, matter cannot be created or destroyed.

9. History of the Law 1700s – Antoine-Laurent Lavoisier
Did experiments in sealed chambers.
Conducted reactions and measured products – just like you!

10. What Happened to Lavoisier?
Executed during the French Reign of Terror -> Guillotined

11. What Happened to Lavoisier?
Unable to complete his experiments
When asked for an extension on his execution, the judge replied, “… the republic has no need of scientists.”

12. What About Volume? Volume: the amount of space a substance takes up.
Units are milliliters (ml)
**Volume is NOT conserved!**

13. Conservation of Matter Practice Questions

14. Cynthia is holding a sheet of paper that has a mass of 2 grams
Cynthia is holding a sheet of paper that has a mass of 2 grams. She tears the sheet of paper into many small pieces. Which of the following is true?
The sum of the mass of all the pieces of paper is less than 2 grams.
The sum of the mass of all the pieces of paper is more than 2 grams.
Each piece of paper has a mass of 2 grams.
The sum of the mass of all the pieces of paper is 2 grams.

15. Cynthia is holding a sheet of paper that has a mass of 2 grams
Cynthia is holding a sheet of paper that has a mass of 2 grams. She tears the sheet of paper into many small pieces. Which of the following is true?
The sum of the mass of all the pieces of paper is less than 2 grams.
The sum of the mass of all the pieces of paper is more than 2 grams.
Each piece of paper has a mass of 2 grams.
The sum of the mass of all the pieces of paper is 2 grams.

16. Lyle stirs 5. 0 grams of salt into a beaker of water. He then adds 15
Lyle stirs 5.0 grams of salt into a beaker of water. He then adds 15.0 grams of pure iodine to the mixture. If the total mass of the new mixture is 225 grams, what is the mass of the water?
20 grams
205 grams
200 grams
100 grams

17. Lyle stirs 5. 0 grams of salt into a beaker of water. He then adds 15
Lyle stirs 5.0 grams of salt into a beaker of water. He then adds 15.0 grams of pure iodine to the mixture. If the total mass of the new mixture is 225 grams, what is the mass of the water?
20 grams
205 grams
200 grams
100 grams

18. What should Sally guess as the new mass of the glass of sugar water?
Sally’s teacher tells her to find the masses of a sugar cube and a glass of water. Sally finds the masses to be 10 g for the sugar cube and 100 g for the glass of water. Then, the teacher tells her to put the sugar cube into the water. Sally puts the cube into the glass of water and watches as it dissolves. Then, the teacher tells Sally to estimate the new mass of the glass of sugar water.
What should Sally guess as the new mass of the glass of sugar water?
200 g
50 g
110 g
90 g

19. What should Sally guess as the new mass of the glass of sugar water?
Sally’s teacher tells her to find the masses of a sugar cube and a glass of water. Sally finds the masses to be 10 g for the sugar cube and 100 g for the glass of water. Then, the teacher tells her to put the sugar cube into the water. Sally puts the cube into the glass of water and watches as it dissolves. Then, the teacher tells Sally to estimate the new mass of the glass of sugar water.
What should Sally guess as the new mass of the glass of sugar water?
200 g
50 g
110 g
90 g

20. In the chemical reaction below, sodium (Na) and chlorine (Cl) combine to form sodium chloride (NaCl).
2Na + Cl2  2NaCl
If the combined mass of the starting reactants is 50 grams, then the mass of sodium chloride formed once the reaction has reached completion
will be between 50 and 100 grams.
will be less than 50 grams.
will be exactly 100 grams.
will be exactly 50 grams.

21. In the chemical reaction below, sodium (Na) and chlorine (Cl) combine to form sodium chloride (NaCl).
2Na + Cl2  2NaCl
If the combined mass of the starting reactants is 50 grams, then the mass of sodium chloride formed once the reaction has reached completion
will be between 50 and 100 grams.
will be less than 50 grams.
will be exactly 100 grams.
will be exactly 50 grams.