Download ANSWER KEY Chemistry CPA Final Exam Study Guide Final Exam

ANSWER KEY
Chemistry CPA Final Exam Study Guide
Final Exam Date: Wednesday, June 17, 2015
Exam Time: 10:15 – 12:00 pm
Topic List
Chemical Reactions
 Parts of a reaction
 Identify the types of reactions
 Balance
 Write the formula equation if you are given a word equation
Mole






Molar Mass
Convert moles-grams and grams-moles
Percent Composition
Stoichiometry
Limiting Reactant
Percent Yield


Solubility Curves
Molarity
Solutions
Gas Laws and KMT
 Kinetic Molecular Theory
 Heating/Cooling Curves
 Boyle
 Charles’
 Gay-Lussac
 Ideal
Acid/Base


Properties
Calculate pH and pOH and find [H+] and [OH-]
Exam Structure
o Part 1 = 80 points: Multiple choice questions
o Part 2 = 20 points: Open-Ended/Free Response
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
You will be given the following formula sheet and a periodic table.
Mole Conversion
Given unit
Desired unit
x _____________
Given unit
Percent Composition =
Mass of element
Molar mass
Percent yield = actual
theoretical
x 100
x 100
Gas laws
Temperature in Kelvin = °C + 273
P1V1=P2V2
T1V2 = T2V1
T1P2 = T2P1
𝐿∙𝑎𝑡𝑚
PV = nRT, where R = 0.0821𝐾∙𝑚𝑜𝑙
Molarity
moles
M
L
Acids & Bases
pH + pOH = 14
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
Unit 5: Chemical Reactions
1. What does the law of conservation of mass state? matter is neither
created nor destroyed.
2. Why is it necessary to balance a chemical equation? number of atoms
on each side of the equation must be equal.
3. What is the difference between a word equation and a chemical equation?
Give an example of each. word equation uses chemical names,
chemical equation uses chemical formulas and symbols.
Complete the chart
Symbol
Explanation
+
Used to separate two reactants or two products

Yields, separates reactants and products
(s), (l), (g)
(aq)
States of matter; Fe (s)
Aqueous solution – dissolved in water
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
4. Identify the type of reaction and balance the reaction.
A)
__2__ NaBr + ____ Ca(OH)2  ___ CaBr2 + __2__ NaOH
Type of reaction: _double replacement_________________
B)
___2_ NH3+ ____ H2SO4  ____ (NH4)2SO4
Type of reaction: ___synthesis__________________
C)
__2__ C5H9O + __15__ O2  __10 CO2 + _12___ H2O
Type of reaction: combustion_____________________
D)
__3__ Pb + ___2_ H3PO4  ___3_ H2 + ____ Pb3(PO4)2
Type of reaction: ___single replacement____________
E)
____ Li3N + ____ NH4NO3  ___ LiNO3 + ___ (NH4)3N
Type of reaction: _____double replacement________
F)
__2__ HBr  ____H2
+ ____Br2
Type of reaction: ____decomposition_________________
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
5. Balance the reaction: Ag + HNO3 
A. 1:1:1:1:1
AgNO3 + H2O + NO2
B. 2:2:2:2:1
C. 2:1:2:2:2
D. 1:2:1:1:1
E. none
6. Given the following word equations, right a formula equation. Then
identify the type of reaction:
A. Sodium metal and chlorine gas react to form sodium chloride
crystals
2 Na(s) + Cl(2) 2 NaCl (s)
B. propane gas and oxygen gas react to form carbon dioxide, water
vapor, and energy.
C3H8(g) + 5 O2(g)  3 CO2 + 4 H2O + energy
C. zinc metal reacts with hydrochloric acid to form zinc chloride
solution and hydrogen gas.
Zn (s) + 2 HCl  ZnCl2 + H2 (g)
Lab Questions: Know/be able to do:
 Know the signs of a chemical reaction
 Know the five classifications of a chemical reaction
 Know the activity of metals
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
Unit 6: Moles
Match each item with the correct statement below.
a.
b.
c.
d.
particle
mole
Avogadro's number 6.02 x 1023
percent composition
7. __C____ the number of particles of a substance present in 1 mole of that
substance
8. __A____A term to describe an atom, ion, or a molecule
9. ___B___the SI unit used to measure amount of substance
10. ___D____the percent by mass of each element in a compound
Molar Mass (use your periodic table)
11. What is the molar mass of AuCl3?
303.32 g
12. What is the molar mass of (NH4)2CO3
96.11 g
13. What is the molar mass of barium?
137.33 g
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
Moles and Mass (use the molar mass to convert to moles or grams)
14. What is the mass in grams of 5.90 moles of C8H18
674.13 g
15. What is the mass in grams of 9.32 moles of He?
37.28 g
16. What is the number of moles in 432 g Ba(NO3)2?
1.65 mol
17. What is the number of moles of beryllium in 36 g of Be?
4.0 mol
Percent Composition (use the molar mass to calculate the percent of the
element)
18. What is the percent composition of chromium in BaCrO ?
54.2%
19. What is the percent of carbon in acetone, C H O?
62.0%
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
Stoichiometry
MgCl2 + 2 NaOH  Mg(OH)2 + 2 NaCl
20. Balance the above reaction.
21. What is the mole ratio of MgCl2 to NaOH?
1:2
22. Identify the limiting reactant if 2 mole of MgCl2 and 2 mole of NaOH are
used in a reaction.
NaOH is limiting reactant
2 Li
+ 2 H(OH)  2 LiOH + H2
23. Balance the above reaction.
24. What is the mole ratio of Li to water?
2:2
25. Identify the limiting reactant if 2 mole Li and 2 mole of water are used in a
reaction.
no limiting reactant.
Lab Questions – Know/be able to do:
 If you are given grams from lab data, convert to moles
 How to determine the mole ratio from lab data (Moles of Fe and Cu
lab)
 Predict the products of a single-replacement reaction:
o Mg + HCl  ________ + _________ ?
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
Unit 7: Solution Chemistry
26. Given grams how do you solve for moles? Example: convert 90 grams of
water to moles.
divide the given by the molar mass:
90 g / 18 g = 5 mol
27. Molarity is equal to __.
a. Grams of solute / moles of solute
b. Volume of solution x moles of solute
c. Moles of solute / liters of solution
d. Volume of solution / grams of solute
28. What mass of methanol, CH3OH, must be dissolved to make 1.50 L of a
0.675M solution? SHOW YOUR WORK!!!!
1. Find mol first: 0.675x1.50 = 1.01 mol
2. then convert to gramsmol = 1.01 mol x 32.05 g = 32.37 g
29. What is the molarity of a solution of HNO3 that contains 250 grams HNO3
in 3 L of solution? Convert grams to moles first.
1. Convert grams  moles: 250 g/63.02 g = 4.0 mol
2. solve for M: 4.0 mol/3 L = 1.3 M
30. What volume of 18.0 M H2SO4 is needed to contain 200 g H2SO4?
Convert grams to moles first.
1. Convert grams  moles200 g/98.08 g = 2.03 mol
2. Solve for V= 2.03/18.0 = 0.11 L
31. How many moles of CaCl2 are required to prepare 2.00 liters of 0.700 M
CaCl2?
1.4 mol
Chemistry CPA Final Exam Study Guide
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ANSWER KEY
32. How many grams of NaI would be used to produce a 2.0 M solution with a
volume of 1.0L? Solve for moles and convert your answer to grams.
1. Find moles: 2.0x1.0 = 2.0
2. Convert moles  grams: 2.0 x 149.89 = 299.78 g
Chemistry CPA Final Exam Study Guide 10
ANSWER KEY
Use this solubility curve to answer the next set of questions (#33- 37) on
the following page:
Chemistry CPA Final Exam Study Guide 11
ANSWER KEY
33. If there are 100 grams of KNO3 dissolved in 100 g of water at 70oC, the
solution is __.
a. saturated
b. unsaturated
c. supersaturated
34. If there are 10 grams of NaCl dissolved in 100 g of water at 30oC, the
solution is __.
a. saturated
b. unsaturated
c. supersaturated
35. If there are 70 grams of KBr dissolved in 100 g of water at 20oC, the
solution is __.
a. saturated
b. unsaturated
c. supersaturated
36. If there are 120 grams of NaClO3 dissolved in 100 g of water at 60oC, the
solution is __.
a. saturated
b. unsaturated
c. supersaturated
37. If there are 190 grams of KNO3 dissolved in 100 g of water at 70oC, the
solution is __.
a. saturated
b. unsaturated
c. supersaturated
Chemistry CPA Final Exam Study Guide 12
ANSWER KEY
Lab Questions: Know/be able to do:
 What “like dissolves like” means
 Polar dissolves polar and nonpolar dissolves nonpolar
 polar and nonpolar do not dissolve
 water is a polar molecule and makes hydrogen bonds
Chemistry CPA Final Exam Study Guide 13
ANSWER KEY
Unit 8: Gas Laws and KMT
Kinetic Molecular Theory and Heating Curves
38. What is the kinetic molecular theory? Gas particles are always in
constant, random motion. The higher the temperature, the higher the
kinetic energy. Gas particles collide with one another in perfectly
elastic collisions. As temp and KE increase, so do collisions, which
raises the pressure within a gas.
39. How are temperature and kinetic energy related?
When Temperature increases, so does KE and vv.
40. When a substance is in a single state of matter and the temperature is
increasing, there will be an increase in the (kinetic energy/potential
energy) of the particles.
41. When a substance is undergoing a phase change and the temperature is
not changing, there will be an increase in the (kinetic energy/potential
energy) of the particles.
Chemistry CPA Final Exam Study Guide 14
ANSWER KEY
For questions 42 – 45, use the following graph:
42. What is the melting point of:
a. substance A?
350 K
b. substance B?
200 K
43. Which substance will melt first? Substance B
44. What is the boiling point of:
a. substance A? 450 K
b. substance B? 250 K
45. Which substance will boil first? Substance B
Chemistry CPA Final Exam Study Guide 15
ANSWER KEY
The Gas Laws
Gas Law Theory
46. Draw and label the graph for each gas law (Boyle’s, Charles’, GayLussac).
Boyle
Charles
Gay-Lussac
47. Why is it easier to compress a gas than it is to compress liquids or solids?
Gas particles are very spread out and take up more volume even though
their particles are quite small.
48. Why does air escape a tire valve when the cap is removed?
pressure outside the tire is less; systems always move from high to low.
49. Is atmospheric pressure the highest below, at, or very high above sea
level?
highest below sea level, lowest very high above sea level
Chemistry CPA Final Exam Study Guide 16
ANSWER KEY
Gas Law Calculations
50. A 500.0 mL sample of gas is collected at 745.0 torr. What will the volume
be at 760 torr?
Gas Law: ______Boyle__________
(500)(750)/760 = 493.4 L
51. A 2L sample of gas at 100 K is heated to 150 K. What is the new volume?
Gas Law: _______Charles_________
(2)(150)/100 = 3 L
52. If I initially have a gas at a pressure of 12 atm, a volume of 23 liters, and
then I raise the pressure to 14 atm, what is the new volume of the gas?
Gas Law: ________Boyle________
(12)(23)/14 = 19.7 L
53. A gas takes up a volume of 17 liters, and a temperature of 299 K. If I raise
the temperature to 350 K what is the new volume of the gas?
Gas Law: _______Charles_________
(17)(350)/299 = 19.9 L
Chemistry CPA Final Exam Study Guide 17
ANSWER KEY
54. I have a gas at a volume of 0.5 L and a temperature of 325 K. If I raise
the volume to 1.2 L, what will be the new temperature?
Gas Law: _______Charles_________
(325)(1.2)/0.5 = 780 K
55. If I have 21 liters of gas at a temperature of 900 K, what will be the volume
of the gas if I decrease the temperature to 750 K?
Gas Law: __________Charles______
(21)(750)/900 = 17.5 L
56. If I have a sample of gas at 300 K and a pressure of 5 atm, what will be
the temperature of the gas if I decrease the pressure to 3 atm?
Gas Law: _________Gay-Lussac_______
(300)(3)/5 = 180 K
57. A gas occupies a fixed volume at 285 K at 1 atm. If the pressure
increases to 3 atm, what is the new temperature?
Gas Law: _________Gay-Lussac_______
(285)(3)/(1) = 855 K
Chemistry CPA Final Exam Study Guide 18
ANSWER KEY
58. A sample of nitrogen gas (N2) occupies a volume of 0.25 L at a pressure
of 2 atm and 22°C. How many moles of N2 gas are there in this sample?
Gas Law:_____________Ideal___
T = 22 + 273 = 295
n = PV/RT
(2x0.25)/(0.0821x295)
= 0.021 mol
59. How many grams of N2 gas are there in question 66? (Hint: use moles to
grams conversion!)
0.021 mol x 28.02g/1mol = 0.59 g
60. A 4.5 mole sample of gas occupies a volume of 1.3 L at a temperature of
293 K. What is the pressure of the gas?
Gas Law:_______Ideal_________
P = nRT/V
= (4.5)(0.0821)(293)/1.3
= 83.3 atm
Chemistry CPA Final Exam Study Guide 19
ANSWER KEY
Unit 9: Acids & Bases
61. List the properties for acids below.
Sour, pH below 7, caustic, react with metals, produce H+ ions in solution,
electrolyte/conducts electricity, turn litmus paper red
62. List the properties for bases below.
Bitter, pH above 7, caustic, produce OH- ions in solution,
electrolyte/conducts electricity, turn litmus paper blue
63. What happens when an acid is mixed with a base? (Write the general form
for the reaction that happens) neutral products are formed:
Acid + base  salt + H2O
64. What is the range of the pH scale? 0-14
65. What is the pH range for acids? 0-6.9
66. What is the pH range for bases? 7.1-14
67. What is the pH for a neutral solution? 7
68. pH + pOH = 14
Chemistry CPA Final Exam Study Guide 20
ANSWER KEY
69. Complete the chart
pH
pOH
11
3
Acid , Base,
Neutral
base
7
7
neutral
12
2
base
2
12
acid
Chemistry CPA Final Exam Study Guide 21
ANSWER KEY
70. Review the sample data table below from a student’s lab and answer the
following questions.
Test Property
Test Solutions
A
B
C
Conductivity
Very strong
Very strong
none
Litmus Paper
Turns Red
Turns Blue
No change
Phenolphthalein
colorless
Pink color change
colorless
4.0
10.0
7.0
Red
Purple
Green
Produces a gas
none
none
pH Test Paper
Universal Indicator
Reaction with Magnesium
Chemistry CPA Final Exam Study Guide 22
ANSWER KEY
Questions to go with the #62 Data Table:
A. Is Solution A an acid, base, or neutral? Why?
Acid; pH below 7, universal indicator turns red, reacts with magnesium and
produces hydrogen gas.
B. Is Solution B an acid, base, or neutral? Why?
Base; pH above 7, turns ppt pink, turns universal indicator purple, doesn’t
react with Mg
C. Is Solution C an acid, base, or neutral? Why?
Neutral; pH is 7, doesn’t conduct a current, turns universal indicator green,
doesn’t react with Mg
D. What are the chemical properties that this student tested?
Reaction with Mg
E. What are the physical properties that this student tested?
Conductivity, pH, litmus, phenolphthalein
F. What were the qualitative observations this student made?
Conductivity, litmus, phenolphthalein, reaction with Mg
G. What are the quantitative observations this student made?
pH test paper
Chemistry CPA Final Exam Study Guide 23