Download Mass-Mass Stoichiometry

Chem Regular Second Semester Final Exam Review
This review is simply a guide. Anything we’ve covered is considered “fair game” on the final. However, we did try to
give example problems from all the topics we’ve studied. So if you run across something during your studying that is not
found on this sheet, please bring it to our attention.
The resources you will be using for the final exam will include the periodic table, your ion list, and a calculator.
Good luck studying! If you’ve kept up all along, you’ll do fine with this review sheet. If you’ve had trouble, I suggest you
find a study buddy to re-teach you the things you’re still confused with. Plan your study time NOW so that you’ll leave
enough time for each class. Also, make your study session calendars with classmates now so that your schedule works out
for you!
Stoichiometry
Mole-Mole Stoichiometry
1. Given the following reaction….
Mg + O2 --- MgO
a) If we react 0.20 moles of Magnesium with an excess of oxygen gas, how many moles of magnesium
oxide should be produced?
b) If in another experiment involving the same reaction 0.75 moles of MgO is
produced, how many moles of Oxygen gas must have been reacted?
Mass-Mass Stoichiometry
2. Given the following reaction…..
Al + Fe2O3 --- Fe + Al2O3
a) If we start with 2.50 grams of Aluminum and an excess of Iron (III) Oxide,
what mass of solid iron should we be able to produce?
b) If we want to produce 50 kilograms of solid iron through this process, what
mass of solid Aluminum is necessary?
3. Given the following reaction….
NaCl (aq) + H2SO4 (aq) ---
Na2SO4(aq) +
HCl(g)
If we start by dissolving 12.0 grams of Sodium Chloride in water, and reacting
this with an excess of Sulfuric acid, what mass of Sodium Sulfate would we
expect to produce?
Other Stoichiometric Conversions
4. Given the following reaction….
N2(g) + H2(g) ----
NH3(g)
a) If we react 40.0 Liters of Nitrogen at STP with an excess of Hydrogen, what volume of ammonia at STP
should we be able to produce?
b) If we react 0.200 Liters of Hydrogen at 400C and 3.50 atm, with an excess of Nitrogen, what mass of
ammonia would we expect to be produced?
c) If we produce 7.50 x 1023 molecules of Ammonia, determine the mass of Nitrogen and the mass of
Hydgrogen that we must have started with.
Law of Conservation of Mass
5. Given the following reaction…..
KClO3(s) --- KCl(s) + O2(g)
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a) If we start with 3.50 grams of Potassium Chlorate, what mass of Potassium Chloride and Oxygen gass
would we expect to produce?
b) How do your results support the law of conservation of mass?
Predicting Products & Writing Reactions
6. Write the equation for the double replacement reaction that occurs between Aluminum Chloride and Silver
Nitrate. Predict which compound will be the precipitate in this reaction. (Use table of Pg. 787 of your book)
7. Write the equation for the double replacement reaction that occurs between Ammonium Sulfide and
Cobalt (II) Nitrate. Predict which compound will be the precipitate in this reaction.
8. Write the reaction for the combustion of HC2H3O2.
Limiting Reagents
9. Given the following reaction…..
Barium Nitrate reacts with Sodium Sulfate to produce Barium Sulfate and
Sodium Nitrate.
If we react 12.0 grams of Barium Nitrate with 6.0 grams of Sodium Sulfate,
A) what mass of Barium Sulfate will we be able to produce?
B) Which reactant is the limiting reagent?
C) How many grams of the excess reagent are left over at the end?
10. Silicon Dioxide is reacted with solid Carbon. This reaction yields Silicon Carbide(SiC) and Carbon Monoxide.
If 50.0 grams of Silcon Dioxide is heated with 30.0 grams of Carbon, what mass of SiC will be produced?
11. Hydrazine, N2H4, is used as a rocket fuel. It reacts with oxygen to form Nitrogen gas and water.
N2H4 + O2 --- N2 + H2O
a) How many liters of N2 at STP form when 1.0 kg of N2H4 reacts with 1.0 kg
of O2?
b) How many grams of the excess reagent remain after the reaction?
% Yield
12. Aspirin, C9H8O4, is made by the reaction of salicylic acid, C7H6O3, and acetic anhydride, C4H6O3.
C7H6O3 + C4H6O3 ---
C9H8O4 + HC2H3O2
a) If We react 57.5 grams of C7H6O3 with an excess of acetic anhydride, what mass of Aspirin would we
expect to collect?
b) If we perform the experiment and we only collect 64.0 grams of aspirin, what is the % yield of our
experiment?
13. When Bismuth reacts with fluorine, the compound BiF3 is produced.
a) If 5.00 g of Bi is reacted with 5.00 g of F2, what is the theorectical yield of BiF3?
b) If the reaction above is performed, and 6.00 grams of BiF3 is collected, what is the % yield of the
experiment?
Atomic Structure
14. What is the relative mass, location and charge of a proton, neutron and electron?
15. For each of the following, determine the mass number, atomic number, number of
2
protons, neutrons and electrons.
a. Ca-40 b. N-15
c. U-235
d. The +1 ion of Na-23
e. The -2 ion of S32
16. What’s the difference between atomic mass and mass number?
17. What is an isotope?
18. Determine the average atomic mass for the following:
Oxygen has three naturally occurring isotopes. O-16 weighs 15.995 amu and is 99.759
percent abundance. O-17 weighs 16.995 amu and is 0.037 percent abundance. O-18
weighs 17.999 amu and is 0.204 percent abundance.
19. Review the history of the atom. (Democritus, Dalton, Thomson, Rutherford, Bohr,
Schrödinger, Chadwick, are the most important.) Review their experiments, if relevant,
and the significance of their findings.
20. Identify the four main families(Halogens, Noble gases, Alkalai metals, Alkaline Earth
Metals). Identify Metals, Non-metals, metalloids. Identify Representative Elements,
Transition Metals, Inner-Transition Elements.
21. What’s an anion? What’s a cation?
22. Fill in the chart below for the following NEUTRAL ATOMS:
ISOTOPE
SYMBOL
ATOMIC
NUMBER
8
MASS
NUMBER
NUMBER OF
PROTONS
14
11
23
56
NUMBER OF
NEUTRONS
8
7
21
NUMBER OF
ELECTRONS
20
26
23. There are four naturally occurring isotopes of the element chromium. The relative
abundance of each is :
50Cr
52Cr = 83.76%
53Cr = 9.55%
= 4.31%
Calculate the average atomic mass of chromium.
54Cr
= 2.38%
Nuclear Chem
Complete the following nuclear reaction And indicate which type of decay is occurring.
24.
241AM --
25.
92U --
He
+
He +
________
231Th
42K --- e +
26.
20Ca
27. List the 3 forms of decay and indicate which the degree of penetration. Give an
example of something that could prevent the penetration of each type of radiation
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28. Oxygen-18 goes through beta decay and becomes Fl-18. The Oxygen 18 isotope has a
half-life of 10 minutes. If we start with 2.0 grams of this isotope how much will remain after 40
minutes?
29. Alpha radiation is also known as a ____________ nucleus. It has an atomic mass of
____________ and atomic number of __________.
30. The decay of the radioisotope radium-226 produces and isotope of the element radon
and alpha radiation. The atomic number of radium (Ra) is 88; the atomic number of radon
(Rn) is 86. Write the equation for this process
31. Suppose you have a radioactive isotope with a half-life of 2 years and you start with 800
grams of this substance today. How long will it take before you have 100 grams of this
substance? How long will it take before you have 25 grams?
32. Write the nuclear equations for the following:
the alpha decay of thorium-230
The beta decay of hydrogen-3
33. A ______________ reaction occurs in a nuclear reactor. It is the splitting/joining of atoms.
(circle)
34. A _______________ reaction occurs on the sun. It is the splitting/joining of atoms.(circle)
Gases and Gas Laws
35. What four variables affect the behavior of a gas?
36. Know the relationships (direct or inverse) between each pair of the four variables
37. What’s the molar mass of the following:
a. O2
b. CO2
c. Rn
d. Fe(NO3)3
e. Al2(SO4)3
38. How many moles are in a 45.0 L sample of O2 at STP?
39. What is the volume of a 0.77 mol sample of Ne gas at STP?
a. How many Ne particles would this be?
b. What would the mass of this sample be?
40. How many particles would there be in a 134 gram sample of HCl?
41. What is the pressure(in atm)exerted by a 54 g sample of radon gas in a 35 L tank if the
temperature is 100˚C?
42. Review the kinetic molecular theory of gases and the gas laws!
43. What happens to the pressure of the sample above if the temperature is raised to 25˚C
and the volume increases to 62.0 L?
44.The air in a hair spray bottle is at 2.50 atm of pressure when the temperature is 25C. If the
bottle is thrown into a fire, what will the pressure be when the temperature is raised to 250C?
45. A gas sample measure 400 mL at 0˚C. At what temperature will it occupy a volume of
270 mL?
46. A gas bubble has a volume of 2.00mL at the bottom of a lake, where the pressure is 3.40
atm. What is the volume of the bubble at the surface of the lake, where the pressure is 1.00
atm? Assume that the temperature is constant.
47. If 2.00 L of of Carbon monoxide (CO) is collected at STP, how many grams of CO will
have been collected?
48. Volume increases, the pressure will ______________
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49. Pressure decreases, temperature will _______________
50. Temperature increases, volume will _______________
51. What is Boyle’s Law? Charles Law? John’s Law? Combined Law? Avogadro’s Law?
Food / Energy
a)
2 CO (g)
+
O2 (g) 
2 CO2 (g) +
540.8 kJ
b)
H2O
+
C
+
131.3 kJ

c)
C
+
O2

CO2
H = -392.9 kJ
d)
N2
+
2 O2

2 NO2
H = +67.7 kJ
e)
C
+
2 H2

CH4
74.8 kJ released
CO
+
H2
52. Which reactions are endothermic?
53. What is the H for reactions a, b, and e?
54. Which reactions have products that have lower potential energy than the reactants?
55. Rewrite reactions “c” and “d” to include energy as a term within the balanced equation.
56. Draw an energy diagram that might represent the reaction taking place in “b”.
57. What quantity of energy in kJ is released in reaction “a” when 15 moles of CO react completely?
58. What quantity of energy in kJ is necessary in reaction “b” for 15.7 g of carbon to react?
59. What mass of methane is produced when 143 kJ are released?
60. Write the reaction for the complete combustion of hexane. Include energy in the reaction. (Use
book and be careful…how many moles of hexane do you end up with in the balanced reaction?)
Use reaction “a” to answer #10-12:
61. How many kJ are released when 2 moles of carbon monoxide are burned?
62. Convert #12 to kilocalories.
63. How many kJ are released when 258.3 g of CO are burned with sufficient oxygen?
64. An experiment is performed to determine the Specific Heat Capacity of an unknown
metal. The 55.0 gram piece of metal is placed in a boiling water bath. Meanwhile, a
calorimeter is filled with 80.0 mL of water. The temperature of the water in the calorimeter is
determined to be 25.0C. The metal is then quickly removed from the hot water bath and
placed in the calorimeter. After being allowed to come to equilibrium, the final temperature
of the metal and the water in the calorimeter is determined to be 26.7C. Using the data
from this experiment determine the Specific Heat of the metal.
65. How much heat is transferred when 750 g of water is heated from 23C to 63C?
66. If 400 J of energy is added to a 10. gram sample of water….how much will it’s
temperature increase?
67. How much heat energy is needed to raise the temperature of a 85 g sample of copper
from 22.4C to 75.6C? Specific heat capacity of Cu = 0.29 J/gC.
68. Know the functional groups….alcohol, amino, carboxylic acid, ester.
69. Know the structure of a protein.
70. Know the difference between malnourished and undernourished.
71. What is a saturated fat? Unsaturated fat?
72. Convert 2,500 Joules into….KiloJoules? calories? Calories?
Random other stuff that might be useful
73. Find the molar mass of the following compounds.
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a. CuSO4
b. Ba3(PO4)2
74. Review the layers of the atmosphere.
75. What does synergism mean?
76. What causes acid rain? What is smog?
c. P2O5
77. What are the 5 types of reactions we discussed? Be able to identify each type.
78. What is the purpose of balancing a reaction? What type of number is used to do so?
79. Identify and balance the following reactions:
a. C12H26
+
O2

H2O +
CO2
b. CuCl2
+
Al

AlCl3 +
Cu
c. H2
+
I2

HI
d. SnCl2
+
Cl2

SnCl4
e. CaCO3 +
HCl 
CaCl2 +
H2CO3
f. Solid Sodium reacts with water to produce Sodium Hydroxide and Hydrogen gas.
80. Review acids and bases. The pH scale.
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