1. Stoichiometry Review

2. Which equation is not balanced?
2H2 + O2  2H2O
4H2 + 2O2  4H2O
H2 + H2 + O2  H2O + H2O
2H2 + O2 + H2O

3. Which coefficients correctly balance the equation NH4NO2  N2 + H2O
1,2,2
1,1,2
2,1,1
2,2,2

4. When the equation Fe3O4 + Al  Al2O3 + Fe is correctly balanced, the coefficient of Fe is7 9

5. The units of molar mass are
g/mol
mol/g
amu/mol
amu/g

6. In the reaction represented by the equation N2 + 3H2  2NH3, what is the mole ratio of nitrogen to ammonia?
1:1
1:2
1:3
2:3

7. In the reaction represented by the equation 2Al2O3  4Al + 3O2, what is the mole ratio of aluminum to oxygen?
10:6
3:4
2:3
4:3

8. In the reaction represented by the equation C + 2H2  CH4, what is the mole ratio of hydrogen to methane?
1:1
2:1
1:2
2:4

9. According to the Haber process equation, N2 + 3H2  2NH3, how many moles of nitrogen gas are required to completely convert 9.0 mol hydrogen gas to ammonia?
1.0mol
2.0mol
3.0mol
6.0mol

10. In the equation 2KClO3  2KCl + 3O2, how many moles of oxygen are produced when 3.0mol KClO3 completely decompose?
1.0mol
2.5mol
3.0mol
4.5mol

11. 1 mole of oxygen has 6.022 x 1022 atoms 6.022 x 1023 atoms

12. What is the molar mass of magnesium sulfate? The sulfate ion is SO42-.
72 g/mol
120 g/mol
240 g/mol
140 g/mol

13. Calculate the mass in grams of 0.0091 moles of Sr(NO3)2.

14. Calculate the mass in grams of 9.96 x 1026 atoms of iron.

15. Calculate the percent composition of Al(OH)3.

16. What is the empirical formula of a compound with 24. 3% Fe, 33
What is the empirical formula of a compound with 24.3% Fe, 33.9% Cr, and 41.8% O?
FeCrO
FeCrO5
Fe2Cr3O12
FeCr3O6

17. What is the empirical formula of a compound with 41. 39% C, 3
What is the empirical formula of a compound with 41.39% C, 3.47% H, and the remainder O?
CHO
C2H3O
C7HO
C6H12O6

18. What is the molecular formula of a compound with an empirical formula of CHO and a molecular mass of amu?
CHO
C4H4O4
C4H4O
C2H4O2

19. Phosphorus burns in air to produce a phosphorus oxide in the following reaction: 4P + 5O2  P4O10 What mass of phosphorus will be needed to produce 3.25 moles of P4O10?
0.104 g
0.026 g
403 g
25 g

20. What mass of aluminum will react with 150
What mass of aluminum will react with 150. g of iron(III) oxide to produce iron and aluminum oxide according to the equation below: 2Al + Fe2O3  2Fe + Al2O3
50.6 g
8100 g
25.3 g
12.7 g

21. If 3. 00 g of nitrogen reacts with 3
If 3.00 g of nitrogen reacts with 3.00 g of hydrogen, what mass of ammonia is produced for the reaction: N2 + 3H2  2NH3
34.0 g
7.3 g
3.6 g
6.0 g

22. For the reaction represented by the equation 2Na + H2O  2NaOH + H2, how many grams of sodium hydroxide are produced from 3.0mol of sodium with an excess of water?
40.g
80.g
120.g
240.g

23. For the reaction represented by the equation CH4 + 2O2  CO2 + 2H2O, how many moles of carbon dioxide are produced from the combustion of 100.g of methane?
6.23 mol
10.8 mol
12.5 mol
25.0 mol

24. A chemical reaction involving substances A and B stops when B is completely used. Substance B is the
excess reactant
limiting reactant
primary reactant
primary product

25. When the limiting reactant in a chemical reaction is completely used, the
excess reactants begin combining
reaction slows down
reaction speeds up
reaction stops

26. What is the maximum possible amount of product obtained in a chemical reaction?
theoretical yield
percentage yield
mole ratio
actual yield

27. For the reaction SO3 + H2O  H2SO4, calculate the percentage yield if 500.g of sulfur trioxide reacts with excess water to produce 575g of sulfuric acid in lab.
82.7%
88.3%
91.2%
93.9%

28. For the reaction Mg + 2HCl  MgCl2 + H2, calculate the percentage yield of magnesium chloride if 100.g of magnesium react with excess hydrogen chloride to yield 330.g of magnesium chloride in lab.
71.8%
74.3%
81.6%
84.2%

29. The molar mass of LiF is 25. 94g/mol
The molar mass of LiF is 25.94g/mol. How many moles of LiF are present in 10.37g?
0.3998mol
1.333mol
2.500mol
36.32mol

30. How many molecules are there in 5.0g CH3OH?
9.4 x 1022
3.0 x 1024
3.6 x 1024
3.8 x 1024

31. What is the mass percentage of chlorine in NaCl?
35.45%
50%
60.7%
64.5%

32. The molecular formula for vitamin C is C6H8O6
The molecular formula for vitamin C is C6H8O6. What is the empirical formula?
CHO
CH2O
C3H4O3
C2H4O2

33. A compound’s empirical formula is N2O5
A compound’s empirical formula is N2O5. If the formula mass is 108amu, what is the molecular formula?
N2O5
N4O10
NO3
N2O4x