1. Stoichiometry Chapter 3

2. Avogadro’s Number NA 6.022 X 1023 6.022 X 1023 H atoms = 1.008 g H
6.022 X 1023 O atoms = g O

3. The mole
1 mole = X 1023 atoms
1 mole H = X 1023 H atoms = g H
1 mole Cl2 = X 1023 Cl2 molecules = g Cl2
1 mole e- = X 1023 e-

4. Molar mass
MM,GMM,
Is numerically equal to the sum of the masses of the atoms in the formula
CaCl2 = g/mol

5. Mass-mole conversions Calculate the mass in grams of 13.2 mol CaCl2

6. Mass-mole conversions Calculate the mass in grams of 13.2 mol CaCl2

7. Calculate the number of moles in 16.4 g C6H12O6

8. Calculate the number of moles in 16.4 g C6H12O6

9. Molarity
Concentration of a solute in a solution
[ ]
M =

10. What volume of 12 M HCl must be taken to obtain 0.10 mol HCl?

11. What mass of NaOH is contained in 125mL of a 6.00 M NaOH solution?

12. What are the molarities of Al 3+ and SO42- in 0.100 M Al2(SO4)3 ?

13. What is the percent composition of K2CrO4 ?

14. What is the percent composition of K2CrO4 ?
MM = 2(39.10) (16.00) = g/mol

15. What is the percent composition of K2CrO4 ?
MM = 2(39.10) (16.00) = g/mol

16. Empirical formula-simplest
Assume a 100 g sample unless otherwise stated
Convert grams to moles
Find the mole ratio

17. Find the empirical formula of a compound containing 26. 6 % K, 35
Find the empirical formula of a compound containing 26.6 % K, 35.4 % Cr, and 38.0 % O

20. A sample of acetic acid weighing 1. 000 g burns to give 1
A sample of acetic acid weighing g burns to give g CO2 and g H2O. Find the empirical formula.

21. A sample of acetic acid weighing 1. 000 g burns to give 1
A sample of acetic acid weighing g burns to give g CO2 and g H2O. Find the empirical formula.
CxHyOz O CO H2O
1.000 g g g
Find the mass of C from CO2
Find the mass of H from H2O
Find the mass of O by difference

25. Molecular formulas
Must be told the molar mass
MM/FM

26. Find the molecular formula of acetic acid. MM = 60 g/mol

27. Chemical Equations Balancing
The coefficients of a balanced equation represent numbers of moles of reactant and products

28. Combustion of propane in air
C3H8 + O CO2 + H2O

29. Combustion of propane in air
C3H8 + O CO2 + H2O

30. Combustion of propane in air
C3H8 + O CO2 + 4H2O

31. Combustion of propane in air
C3H8 + 5O CO2 + 4H2O

32. Combustion of propane in air
C3H8 (g) + 5O2 (g) CO2 (g) + 4H2O (l)

33. How many moles of CO2 are produced when 1.65 mol C3H8 burns?

34. How many moles of CO2 are produced when 1.65 mol C3H8 burns?

35. What mass of O2 is required to react with 12.0 g C3H8

36. What mass of O2 is required to react with 12.0 g C3H8

37. Limiting reactant Determines the amount of product formed
It is completely used up
Is used to determine the theoretical yield
The other reactant is in excess
There will be some left over

38. Calculate the theoretical yield of AgI and determine the limiting reactant of a reaction between 1.00 g Ag and 1.00 g I2

39. Calculate the theoretical yield of AgI and determine the limiting reactant of a reaction between 1.00 g Ag and 1.00 g I2
2Ag(s) + I2(s) AgI(s)

40. Calculate the theoretical yield of AgI and determine the limiting reactant of a reaction between 1.00 g Ag and 1.00 g I2
2Ag(s) + I2(s) AgI(s)

41. 1.85 g AgI is the theoretical yield
I2 is the limiting reactant
Ag is in excess

42. How much Ag is in excess?

43. What is the percent yield if the actual yield was 1.50 g AgI?