1. Law of Conservation of Mass

2. Counting Atoms
Count the number of atoms in the following chemical formula:
6H2O

3. Counting Atoms
Count the number of atoms in the following chemical formula:
7MnO4

4. Counting Atoms
Count the number of atoms in the following chemical formula:
4HNO3

5. Counting Atoms
Count the number of atoms in the following chemical formula:
Al2O3

6. Counting Atoms
Count the number of atoms in the following chemical formula:
5Al2O3

7. Counting Atoms
Count the number of atoms in the following chemical formula:
H2O + H2O

8. Counting Atoms
Count the number of atoms in the following chemical formula:
4H2O + 3H2O

9. Counting Atoms
Count the number of atoms in the following chemical formula:
4H2O + H2O

10. Counting Atoms
Count the number of atoms in the following chemical formula:
H2O + MnO4

11. Counting Atoms
Count the number of atoms in the following chemical formula:
3H2O + 2MnO4

12. Counting Atoms
Count the number of atoms in the following chemical formula:
4H2O + 3MnO4

13. Is it balanced? Prove it!
NaCl  Na + Cl2

14. Is it balanced? Prove it!
H2 + O2  2H2O

15. Is it balanced? Prove it!
2Fe + MnO4  2FeO2 + Mn

16. Is it balanced? Prove it!
N2O5 + H2O  2HNO3

17. Is it balanced? Prove it!
2H2O2  2H2O + O2

18. Subscript vs. Coefficient
N2O5 + H2O  2HNO3 ? ?

19. Which of the following rules do we use when balancing chemical equations?
A. Law of Conservation of Atoms B. Law of Conservation of Mass C. Law of Conservation of Products D. Law of Conservation of Reactants.

20. Which of the following do you change to balance an equation?
Subscript
Elements
Compounds
Coefficients

21. Which coefficient would I add to balance the chemical equation?
6AlBr3 + 3N2  2Al3N3+ ?Br2 3 6 7 9

22. Which coefficient would I add to balance the chemical equation?
2C2H6 + 7O2  4CO2 + ?H2O 5 6 7 14

23. A chemical equation is shown below: 2Zn + 2HCl  2ZnCl + H2 + heat
A chemical equation is shown below: 2Zn + 2HCl  2ZnCl + H2 + heat. The element zinc (Zn) can best be described as:
A. compound B. mixture C. gas D. reactant

24. A chemical equation is shown below
A chemical equation is shown below. C6H12O6 + 6O2  6CO2 + 6H2O What are the products of the reaction?
A. H2O and O2 B. C6H12O6 and CO2 C. CO2 + H2O D. C6H12O6 + O2

25. Balance the following equation:
__PbO + __C  __Pb + __CO2

26. Balance the following equation:
__Na3N  __Na + __N2

27. Balance the following equation:
__P4 + __O2  __P2O5

28. Balance the following equation:
__Al2O3  __Al + __O2

29. Balance the following equation:
__Fe + __H2O  __Fe3O4 + __H2

30. Balance the following equation:
__H2O2  __H2O + __O2