1. 6.02 X 1023
Avogadro’s Number

2. 6.02 X 1023
1 Mole

3. 3.01 X 1023
0.5 Mole

4. 1.50 X 1023
0.25 Mole

5. 12.04 X 1023 Or
1.204 X 1024
2.0 Mole

6. 22.4 Liters
1.0 Mole of any gas at STP

7. Standard Temperature = 0C Standard Pressure = 1 atm
STP

8. 11.2 Liters
0.5 mole of any gas

9. 44.8 Liters
2.0 mole of any gas

10. 67.2 Liters
3.0 mole of any gas

11. 5.6 Liters
0.25 mole of any gas

12. Sum of the masses of the elements in the compound
Formula Mass

13. Formula Mass of H2O 2 X H = 2 X 1.0 = 2.0 1 X O = 1 X 16.0 = 16.0
Sum = 18.0
Formula Mass of H2O

14. Formula Mass of NH3 3 X H = 3 X 1.0 = 3.0 1 X N = 1 X 14.0 = 14.0
Sum = 17.0
Formula Mass of NH3

15. Formula Mass of CO2 1 X C = 1 X 12.0 = 12.0 2 X O = 2 X 16.0 = 32.0
Sum = 44.0
Formula Mass of CO2

16. Count up the atoms in (NH4)2SO4
For Paren: SubInside X Suboutside
N: 2 S: 1
H: 8 O: 4
Count up the atoms in (NH4)2SO4

17. Count up the atoms in 2Mg3(PO4)2
For Paren: SubInside X Suboutside
Coefficients X subs in formula
Mg: 6 P: 4 O: 16
Count up the atoms in 2Mg3(PO4)2

18. MOLE MAP # of Grams # of Moles # of Particles # of Liters (gas)  by
formula mass
X Formula Mass
# of
Moles
X 22.4 L/mole by
6.02 X 1023
 by
22.4
X 6.02 X 1023
# of
Particles
# of
Liters (gas)

19. Part X 100%
Whole
Percent

20. Part X 100% = X 100%
Whole
Percent H in H2O

21. Part X 100% = X 100%
Whole
Percent O in H2O

22. smallest whole number ratio of the elements in a compound
Empirical Formula

23. Gives exact composition of molecule
Molecular Formula

24. Formula contains all nonmetals
Covalent Compound

25. Formula contains metal plus nonmetal
Ionic Compound

26. CuSO4•5H2O Formula of a hydrated salt. • means “is associated with.”
H2O molecules are stuffed in the empty spaces.
CuSO4•5H2O

27. Formula mass of CuSO4•5H2O
Mass of CuSO4 plus mass of 5 water molecules.
249.6 grams/mole
Formula mass of CuSO4•5H2O

28. Part X 100% = X 100%
Whole
Percent H2O in CuSO4•5H2O

29. All elements to the left of the staircase except H
Metals

30. All elements to the right of the staircase plus H
Nonmetals

31. Compound made from 2 elements
Binary Compound

32. Which formulas are empirical?
H2O H2O2 CH4 C2H6
C6H12O6 KCl P4O10 CaF2
Which formulas are empirical?

33. Given empirical formula & Formula Mass, find Molecular Formula
Find empirical mass
Divide formula mass/empirical mass
Multiply subscripts in empirical formula by answer in step 2
Given empirical formula & Formula Mass, find Molecular Formula

34. Empirical formula = CH & Formula Mass = 78, find Molecular Formula
Empirical mass = 13
Divide formula mass/empirical mass = 78/13 = 6
Multiply subscripts: C6H6
Empirical formula = CH & Formula Mass = 78, find Molecular Formula

35. Mass of H2O = 12 – 8 = 4 g Percent H2O = 4/12 X 100%
Percent salt = 8/12 X 100%
12 grams of hydrated salt is heated. After heating the mass is 8.0 grams. What is the percent salt & the percent H2O?

36. 1 atom of He or 1 mole of He 1 atom per molecule

37. 1 molecule of O2 or 1 mole of O2 2 atoms per molecule

38. 1 molecule of O3 or 1 mole of O3 3 atoms per molecule