1. Law of Conservation of Mass IPC 8.C Investigate and Identify the Law of Conservation of Mass

2. A Chemical Reaction must be balanced. A reaction equation shows the same number and kind of atoms on both sides. ReactantsProducts

3. Al + O 2  Al 2 O 3 http://richardbowles.tripod.com/chemistry/balance.htm

4. __N 2 + __H 2  __NH 3 515 5 13 1

5. Law of Conservation of Mass: The total mass of substances does not change during a chemical reaction. reactant 1 + reactant 2 product total mass = calcium oxide + carbon dioxide calcium carbonate CaO + CO 2 CaCO 3 56.08g + 44.00g100.08g academic.evergreen.edu/curricular/matterandmotion/chem_phys%5Clectures%5Coct5.ppt – ?

6. If a gas is produced in a chemical reaction, it can be difficult to measure its mass if it escapes into the surroundings.

7. The illustrations show a conservation-of-mass experiment. The solution in the beaker lost mass because — A materials have less mass at high temperatures B the mass of the reactants and products was less than 100 g C sodium sulfate (Na 2 SO 4 ) is lighter than air D some of the water molecules turned into gas

8. In the procedure shown above, a calcium chloride solution is mixed with a sodium sulfate solution to create the products shown. Which of the following is illustrated by this activity? F The law of conservation of mass G The theory of thermal equilibrium H The law of conservation of momentum J The theory of covalent bonding

9. To produce 4 molecules of sugar, a plant needs — A 6 molecules of hydrogen B 12 molecules of ATP C 18 molecules of water D 24 molecules of carbon dioxide If one thing in an equation is changed, all other reactants and products must be changed by the same amount. 4 24CO 2 24 H 2 O 24O 2

10. Try all the answer choices to see which one works! What are the coefficients that will balance this chemical equation? A 2, 1, 1 B 3, 4, 2 C 2, 2, 1 D 4, 3, 2 2 1 1 No! 3 4 2 2 2 1 YES!