Exam Final Review
1. Identify Ba(ClO3)2 as which of the following?
a. Acid
b. Base
c. Basic salt
d. Acidic salt
e. Neutral salt
f. None of the above
2. Which of the following reactions corresponds to Gf of NaBr(s)?
a. 2Na(l) + Br2(l) 2NaBr(s)
b. 2Na(s) + Br2(g) 2NaBr(s)
c. Na(s) + Br2(g) NaBr(s)
d. Na(s) + Br2(l) NaBr(s)
e. None of the above
3. The reaction quotient, Qsp, needs to be ________ Ksp for a precipitant to form.
a. Equal to
b. Greater than
c. Less than
d. None of the above
4. The rate of reaction depends on which of the following?
a. Activation Energy (Ea)
b. Change in energy (E)
c. Transition state
d. All of the above
5. What is the oxidation of Cl in NaClO4?
a. +1
b. -1
c. +7
d. -6
e. None of the above
6. Which of the following is the BronstedLowry definition of a base?
a. Proton donor
b. Proton acceptor
c. Electron donor
d. Electron acceptor
e. None of the above
7. Which of the following is TRUE if a reaction has a negative G?
a. The reaction has a large K because the reaction is reactant favored
b. The reaction has a large K because the reaction is product favored
c. The reaction has a small K because the reaction is reactant favored
d. The reaction has a small K because the reaction is product favored
8. A strong acid would have a percent dissociation
a. Near 100%
b. Less than 100%
c. Near 0%
d. Not enough information
9. A catalyst will _________________ an equilibrium.
a. Shift to the right
b. Shift to the left
c. Does nothing to equilibrium
d. None of the above
10. Which of the following is the reducing agent in the reaction below?
Zn(s) + Mg(OH)2(aq) Zn(OH)2(aq) + Mg(s)
a. Zn(s)
b. Mg(OH)2(aq)
c. Zn(OH)2(aq)
d. Mg(s)
e. None of the above
11. Calculus is used to find the Integrated Rate Law
a. True
b. False
12. In a galvanic cell, electrons flow from the cathode to the anode.
a. True
b. False
13. Which of the following is the definition of a Lewis Acid?
a. Proton Donor
b. Contains Hydrogen
c. Electron Acceptor
d. None of the above
14. Kc values have units.
a. True
b. False
15. Rate Constants have units.
a. True
b. False
16. What is the molecularity of the following elementary step? HI(g) + ICl (g) I2(g) + HCl (g)
a. Unimolecular
b. Bimolecular
c. Trimolecular
d. None of the above
17. What is the pH at the equivalence in a titration between a weak base and strong acid?
a. Equal to 7
b. Less than 7
c. Greater than 7
d. None of the above
18. What is the overall order of the reaction if the rate law is: Rate = k[NH4]2[Cl-]
a. Zero
[NH3]
b. First
c. Second
d. Third
e. None of the above
19. Which of the following electronic arrangements will increase the voltage of a system?
a. Parallel
b. Inductive
c. Series
d. Conjunctive
e. None of the above
For the reaction shown below, indicate the direction of shift (left, right, or none) when the
following changes are made:
2 SO2 (g) + O2 (g) 2 SO3 (g)
20. SO2 is added
a. Left
b. Right
c. None
21.Temperature is decreased
a. Left
b. Right
c. None
22. Pressure is increased
a. Left
b. Right
c. None
23. Which of the following is the conjugate acid to Ba(OH)2?
a. Ba
b. OHc. Ba2+
d. None of the above
24. Which of the following is the definition of a catalyst?
a. Consumed in the first step and produced in the last
b. Produced in the first step and consumed in the last
c. Produced in the first step and also produced in the last
d. None of the above
25. It may take several chemical reaction steps to create a complex ion.
a. True
b. False
26. What would you plot in order to find if a reaction is second order with respect to a specific
reactant?
a. ln k versus 1/T
b. [A]t versus t
c. ln [A]t versus t
d. ln k1/k2 versus R
e. 1/[A]t versus t
27. The pH of a buffers range is within _______ of the pKa.
a. 1 unit
b. 2 units
c. 3 units
d. None of the above
28. A reaction that has a positive H and negative S MUST have
a. Positive G at all temperatures
b. Negative G at all temperature
c. Negative G at high temperature, positive G at low temperatures
d. Negative G at low temperatures, positive G at high temperature
e. Not enough information to solve the problem
29. If the reaction quotient, Q, is greater than Kc, then
a. The reaction will proceed forward to reach equilibrium
b. The reaction will proceed in the reverse direction to reach equilibrium
c. The reaction is at equilibrium
d. None of the above
30. Water is an amphoteric substance, meaning
a. It can acts as an acid or base
b. Is neutral
c. Can be consumed
d. None of the above
31. Cell potentials are temperature dependent?
a. True
b. False
32. Only a fraction of collisions result in the formation of the product.
a. True
b. False
33. Which of the following is TRUE, if calcium sulfate (CaSO4) is added to a solution
containing 2.0 M H2SO4(aq)?
a. The solubility of CaSO4does not change
b. The solubility of CaSO4 will increase
c. The solubility of CaSO4 will decrease
d. None of the above
34. Ammonia reacts with water.
a. True
b. False
35. What is the Rate Determining Step in the following reaction mechanism?
N2O5(g)
NO2(g) + NO3(g)
Fast, Reversible
NO2(g) + NO3(g) NO(g) + NO2(g) +O2(g)
Slow
NO(g) + NO3(g) 2NO2(g)
Fast
a. First step
b. Second step
c. Third step
d. None of the above
36. Which of the following is FALSE for a redox reaction?
a. Only oxidation occurs
b. Both oxidation and reduction occurs
c. Redox reaction includes the exchange of electrons
d. All of the above are TRUE
37. Small highly charged metals can be
a. Acidic salts
b. Basic salts
c. Neutral salts
d. None of the above
38.What would you plot in order to find out the activation energy, Ea, for a chemical reaction?
a. ln k versus 1/T
b. [A]t versus t
c. ln [A]t versus t
d. ln k1/k2 versus R
e. 1/[A]t versus t
39. For the reaction 2 SO2(g) + O2(g) 2 SO3(g) at 1 atm pressure, the values of H and S
are both negative, and the process is spontaneous at room temperature. Which of the
following statements is TRUE?
a. G is positive for the reaction at room temperature.
b. G does not depend on temperature.
c. The change in entropy is responsible for the reaction being spontaneous at room
temperature.
d. At high temperatures, H becomes positive.
e. The reaction becomes nonspontaneous at high temperatures.
40. Which of the following salts will change the pH of a solution? Circle ALL that apply!!!
a. NaCl
b. K2CO3
c. NaNO2
d. LiBr
e. KClO4
41. Which of the following is the conjugate base to NH4+?
a. NH3
b. NH2
c. NH5
d. None of the above
42. Spontaneous processes tend to be exothermic.
a. True
b. False
43. Which of the following has the greatest entropy?
a. Gas
b. Liquid
c. Solid
d. None of the above, all the same
44. As temperature is increased, it is observed that the reaction rate increases. This is because:
a. The molecules are closer together.
b. The molecules have more kinetic energy and thus collide more often.
c. The molecules move faster away from each other and collide less often.
d. The molecules expand and touch each other more often.
e. The molecules solidify and solid state reactions are faster.
45. Which of the following is FALSE for polyprotic acids?
a. They are all strong acids
b. They have more than one proton to donate
c. The first protons is easier to remove than the subsequent protons
d. None of the above
46. pH effects the solubility of metal hydroxides.
a. True
b. False
47. Which one of the following reactions would you predict to have a positive value of So?
a. Ba(OH)2(s) + CO2(g) BaCO3(s) + H2O(l)
b. N2(g) + 3H2(g) 2NH3(g)
c. H2O(l) H2O(s)
d. AgNO3(aq) + HCl(aq) AgCl(s) + HNO3(aq)
e. 2SO3(g) 2SO2(g) + O2(g)
48. Which of the following is an Inert Electrode?
a. Diamond
b. Graphite
c. Plutonium
d. None of the above
49. Which of the following is the definition for homogeneous equilibria?
a. All substances in the reaction are in the same phase
b. The substances in a reaction are in different phases
c. The mixture is not completely mixed
d. None of the above
50. Which of the following will NOT affect solubility?
a. Temperature
b. The formation of a complex ion
c. pH
d. None of the above
51. A reaction that has a negative H and negative S MUST have
a. Positive G at all temperatures
b. Negative G at all temperature
c. Negative G at high temperature, positive G at low temperatures
d. Negative G at low temperatures, positive G at high temperature
e. Not enough information to solve the problem
Use the following reduction potentials to answer questions 52 & 53
Reduction Half reaction
Cl2(aq) + 2e2Cl-(aq)
I2(g) + 2e- 2I-(aq)
Br2(s) + 2e- 2Br-(aq)
E(V)
1.36
0.54
1.09
52. Which is the BEST reducing agent?
a. Chlorine
b. Bromine
c. Iodine
d. Cannot determine given this information
53. Which is the BEST Oxidizing agent?
a. Chlorine
b. Bromine
c. Iodine
d. Cannot determine given this information
54. Which of the following pairs of substances will make a good buffer solution?
a. NaCl and HCl
b. HOCl and KOCl
c. KOH and HBr
d. HCN and HCl
e. NH3 and H2O
55. Which of the following is the Second Law of Thermodynamics?
a. Energy cannot be created nor destroyed
b. Any spontaneous process results in a total entropy increase
c. The entropy of a perfectly ordered crystalline substance at 0 K is zero
d. None of the above
56. Whichofthefollowingstatementsistrueif[SO2]=0.754M,[O2]=0.085M,and[SO3]=
1.4M?Giventhisreaction:
2 SO2 (g) + O2 (g) 2 SO3 (g) andKc=756
a.Thissystemisatequilibrium
b.Thissystemmustshifttowardsthereactantstoreachequilibrium.
c.Thissystemmustshifttowardstheproductstoreachequilibrium.
d.Equilibriumcannotbereached.
e.PressureisneededtofindKpfirst,thentheproblemcanbesolved.
57. G changes as a reaction proceeds, while G stays constant.
a. True
b. False
58. By the addition of a common ion which of the following can change?
a. The pH
b. Solubility
c. A shift in the reaction
d. All of the above
59. Water freezing at -25C is
a. Non-spontaneous and increases in entropy
b. Spontaneous and increases in entropy
c. Non-spontaneous and decreases in entropy
d. Spontaneous and decreases in entropy
e. None of the above
60.Which of the following statements is TRUE if the real rate law is rate = k[H2][ICl]:
mechanism:
step one: H2(g) + ICl(g) HI(g) + HCl(g)
step two: HI(g) + ICl (g) I2(g) + HCl (g)
a. Step one is the ratedetermining step and HCl is the intermediate.
b. Step two is the ratedetermining step and HCl is the intermediate.
c. Step one is the ratedetermining step and HI is the intermediate.
d. Step two is the ratedetermining step and HI is the intermediate.
e. Step one is the ratedetermining step and ICl is the intermediate.
Short Answer: You MUST Show Work to get Credit!!! Circle your final answer.
61. What percentage of a sample would remain after 5 half lives?
62. Create a functional Galvanic cell given the following: On the left side of the cell there is lead
(II) nitrate solution with a solid lead electrode. On the right side, there is silver nitrate solution
with a solid silver electrode. Label the following: the anode, cathode, metals, solutions, the
direction of the cations and anions in the salt bridge, and the direction of the electrons.
63. What are the conditions for Standard State?
_______________________
_______________________
_______________________
64. Label the following chemicals as strong acid (SA), strong base (SB),
weak acid (WA), weak base (WB), acidic salt (AS), basic salt (BS), or neutral salt (NS).
a. Ca(OH)2 ______ e. HF ____________
b. HI ______
f. Na2CO3 ________
c. NH4Br _________ g. K3PO4 _________
d. KNO3 ________ h. KCH3COO ______
i. NH3 ___________
j. LiF ____________
k. Ba(Cl)2 ________
l. LiOH ___________
65. When some HCl is added to the solution in number 27, the pH barely changes
because:
a. The OBr ion neutralizes the H+ and produces HOBr.
b. The common ion effect.
c. The HOBr neutralizes the HCl and produces more conjugate base.
d. The conjugate base OH absorbs the HCl.
e. The Na+ ion neutralizes the HCl and produces NaCl.
66. Draw an activation energy diagram on the axis below and label the transition state, the
activation energy, the reactants, the products, and the change in energy for an Exothermic
reaction.
E
reaction
67. Write the formula for the conjugate acid of SO42(aq). ___________
68. Pentane (often used in fuel mixtures) is a volatile substance. (Thats why it easily evaporates
and has a strong odor.) Calculate the boiling point (in oC) of pentane (C5H12), given that its
enthalpy of vaporization (Hvap) is 26.2 kJ and its entropy of vaporization (Svap) is 84.8 J/K.
69. Which of the following salts is least soluble in pure water?
a. CuS, Ksp = 6.3 x 1036
b. Sn(OH)2, Ksp = 5.4 x 1027
c. AgCN, Ksp = 6.0 x 1017
70. Circle the conjugate base in the equation below:
C6H5COOH(l) + H2O(l) C6H5COO(aq) + H3O+(aq)
71. What does SHE stand for?_______________________
72. For the following reaction, H2(g) + Cl2(g) 2 HCl(g) calculate all the equilibrium
concentrations, if the original concentrations were [H2] = 1.55M and [Cl2] = 1.55M, and
Kc = 3.56 x 105.
73. Aspirin, otherwise known as acetylsalicylic acid (ASA), has the formula (C9H8O4). Go for
the dissociation of aspirin in water is 20.1 kJ at 25.0oC. Calculate Ka for aspirin.
74. What volume (in mL) of 0.351 M KOH is needed to reach the equivalence point when
it is titrated with 20.00 mL of 0.452 M acetic acid (CH3COOH)?
a. 7.93 mL
b. 15.0 mL
c. 20.0 mL
d. 25.8 mL
e. 35.1 mL
75. Calculate the pH of a solution made by adding 0.3564 grams of solid lithium cyanide
(LiCN) to 0.9981 L of water. Ka for hydrocyanic acid (HCN) is 4.90 x 1010. Show all
relevant equations, expressions, calculations and circle the answer for full credit.
76. The following experimental data was collected for this reaction:
2 NH3(g) 3 H2(g) + N2(g)
What is the rate law, including rate constant, for this reaction and what is the overall order?
Circle your final answers.
Experiment
1
2
3
Rate (M/s)
3.25 x 10-2
6.47 x 10-2
9.78 x 10-2
[NH3] (M)
0.0500
0.100
0.150
77. Calculate the Standard cell potential, E and Standard Gibbs free energy, G when Mn(s)
reacts with AgNO3(aq) given the following reduction potentials. (Hint: write and balance the
reaction(s))
Half-Reaction
Mn2+(aq) + 2e- Mn(s)
Ag+(aq) + e- Ag(s)
E(V)
-1.18
0.80
78. Calculate [H3O+], [OH], pH, and pOH when 0.0915 moles of nitric acid is placed in
250.0 mL of water.
79. According to the following unbalanced reaction, if the rate of appearance of oxygen gas is
0.125 M/s, what is the rate of disappearance of N2O5(g)? N2O5(g) NO2(g) + O2(g)
80. Predict the signs (+ or ) for Ho, So, Go and spontaneity for the reaction below:
(Hint: what type of reaction is this?)
C2H5OH(l) + 3 O2(g)
Ho _____
3 H2O(g) + 2 CO2(g)
Go ___
So ______
Spontaneous reaction? Yes or No (circle one)
81. What is the pH of a solution made by adding 0.025 M hypobromous acid (HOBr) to
0.010 M sodium hypobromite (NaOBr)? Assume no volume change. Ka = 2.0 x 109
82. The fermentation of glucose produces ethanol and carbon dioxide gas according to the
equation below. Use Gof values in the table below to calculate Gorxn for the fermentation of
glucose at 25oC.
C6H12O6(s)
C6H12O6(s)
C2H5OH(l)
CO2(g)
2 C2H5OH(l) + 2 CO2(g)
Gof (kJ/mol)
-910.0
-174.9
-394.4
83. What is the Kp for the following reaction at 50.5C?
2 SO2(g) + O2(g) 2 SO3(g) and Kc = 654
84. Calculate all equilibrium concentrations of a 0.250 M hydrazoic acid (HN3)
solution? Ka = 1.9 x 105 (Write the reaction for this acid in water for full credit)
85. Write the equilibrium expression Kc and the rate law for the reaction between sodium
carbonate and calcium hydroxide in water.
86. What is the pH of a solution made by adding 25.00 mL of 0.20 M NaOH to 25.00 mL
of 0.20 M HCl?
a. pH = 0.00
b. pH = 1.00
c. pH = 7.00
d. pH = 9.00
e. pH = 13.00
87. What is the reactant concentration after 80.4 seconds for a second order reaction with a
halflife of 4.25 minutes if the initial concentration was 1.476 M?
88. The rate law for a reaction is rate = k[H2]1[F2]1. If the rate is 3.15 x 104 M/s when [H2] =
0.084 M and [F2] = 0.25 M, calculate the rate when [H2] = 0.039 M and [F2] = 0.099 M.
(Hint: find k)
89. Calculate the cell potential, E, at 50.0C if nickel (II) nitrate, Ni(NO3)2, has concentration of
2.25 M and copper (II) nitrate, Cu(NO3)2, has a concentration of 0.15 M, given the following
reduction potentials. (Hint: write and balance the reaction(s))
Half-Reaction
Cu2+(aq) + 2eCu(s)
Ni2+(aq) + 2e- Ni(s)
E(V)
0.34
-0.26
90. Write the chemical reaction for the dissolution of iron (II) hydroxide in water. Then
write the Ksp expression for this salt.
Reaction:
Ksp =
Calculate the molar solubility (S) of iron (II) hydroxide if Ksp= 4.9 x 1017.
91. a) Pyridine is a weak base that is used in the manufacture and pesticides and plastic resins.
Pyridine ionizes in water as follows:
C5H5N + H2O
C5H5NH+ + OH-
The pKb of pyridine is 8.75. What is the pH of a 0.420 M solution of pyridine?
b) Benzoic acid is a weak acid that has antimicrobial properties. Its sodium salt, sodium
benzoate, is a preservative found in foods, medications, and personal hygiene products. Benzoic
acid dissociates in water:
C6H5COOH
C6H5COO- + H+
The pKa of this reaction is 4.2. In a 0.69 solution of benzoic what acid, percentage of the
molecules are ionized?
92. Calculate the pH of 0.535 L of a 0.220 M NH4Cl 0.220 M NH3 buffer before and after the
addition of the following substances. Assume that the volume remains constant.
a) Calculate the initial pH.
b) Calculate the pH after the addition of 0.0055 mol of NaOH.
c) Calculate the pH after the addition of 0.018 mol of HCl.
93. For the reaction of oxygen and nitrogen to form nitric oxide, consider the following
thermodynamic information:
N2(g) + O2(g)
Horxn
Sorxn
2NO(g)
180.5 (kJ/mol)
24.8 J/(K*mol)
a) Calculate the temperature above which this reaction is spontaneous.
b) Calculate the equilibrium constant for the reaction at room temperature, 25oC.
c) The free energy change GT at 2400 K is equal to 1.22 x 105 J/mol. Calculate the equilibrium
constant at 2400 K.
94. What is the proper form of the equilibrium constant expression for the equation;
N2(g) + O2(g)
2NO(g)
95. a) What is the life of a first order reaction with a rate constant of 5.90 x 10-4 s-1?
b) What is the rate constant of a first order reaction that takes 7.40 minutes for the reaction
concentration to drop to half its initial value?
c) A certain first order reaction has a rate constant of 6.30 x 10-3 s-1. How long will it take for the
reaction concentration to drop to 1/8 of its initial value?
96. Classify each salt as acidic, basic, or neutral
a) NaClO__________________
b) NH4Cl__________________
c) Ca(NO3)2________________
97. a) For the following reaction classify each of the following actions by whether it causes a
leftward shift (LS), a rightward shift (RS), or no shift (NS) in the direction of the reaction.
N2(g) + O2(g)
2NO(g)
a) Halve Oxygen____________
b) Double Nitrogen Monoxide___________
c) Double Nitrogen__________
d) Halve Nitrogen_____________
e) Double Oxygen_____________
f) Halve Nitrogen Monoxide__________
b) For the following reaction classify each of the following actions by whether it causes a
leftward shift (LS), a rightward shift (RS), or no shift (NS) in the direction of the reaction.
C(s) + H2O(g)
H2(g) + CO(g)
a) Remove some water____________ d) Remove solid Carbon_____________
b) Add solid Carbon______________ e) Add some water__________________
c) Add Carbon Monoxide__________ f) Remove Carbon Monoxide__________
98. The rate constant of a chemical reaction increased from 0.100 s-1 to 3.30 s-1 upon raising the
temperature from 25.00C to 53.00C.
a) Calculate the value of (1/T2 1/T1)
b) Calculate the value of ln(k2/k1)
c) What is the Activation Energy of the reaction? (express your answer in kJ/mol)
99. a) What is the standard Gibbs free energy for the transformation of diamond to graphite at
298K?
Cdiamond Cgraphite
Substance
Cgraphite
Cdiamond
Hof (kJ/mol)
0
1.897
Sof [J/(K*mol)]
5.740
2.38
b) Based on the answer above, which of these two statements is true (circle your answer).
a) The forward reaction is spontaneous at 298 K.
b) The reverse reaction is spontaneous at 298 K.
100. Write the standard shorthand notation for each of the following cells.
a) Cu2+(aq) + 2Cr(s)
3Cu(s) + 2Cr3+(aq)
________________________________
b) Pb(s) + 2H+(aq)
Pb2+(aq) + H2(g)
___________________________
c) Cl2(g) + Sn2+(aq)
Sn4+(aq) + 2Cl-(aq)
___________________________
101. a) What is the value of A in the following nuclear reaction?_________________
212
84Po
208
82Pb
+ AZX
b) What is the value of Z in the above nuclear reaction?__________________
c) What is the chemical symbol for X in the above nuclear reaction?_________________
102. You need to produce a solution that has a pH of 5.00. You already have 10 mmol
(millimoles) of acetic acid. How many millimoles of acetate (the conjugate base to acetic acid)
will you need to make this solution? The pKa of acetic acid is 4.74. (answer should be in
millimoles)
103. At 25oC phosphoric acid, H3PO4, has the following equilibrium constants
Ka1 = 7.5 x 10-3
Ka2 = 6.2 x 10-8
Ka3 = 4.2 x 10-13
a) What is the pH of a solution of 0.25 M K3PO4, potassium phosphate?
b) What is the pH of a solution of 0.650 M K2HPO4, potassium hydrogen phosphate?
c) What is the pH of a solution of 0.400 M KH2PO4, potassium dihydrogen phosphate?
104. Calculate the pH of the following solutions?
a) 0.50 M of HBr
b) 3.9 x 10-4 M of KOH
c) 5.2 x 10-5 M of Ca(OH)2
105. a)Calculate the value of Kp for the reaction 3A(g) + 3B(g)
temperature of 349oC.
b) Calculate the value of Kc for the reaction X(g) + 3Y(g)
of 143oC.
3Z(g) when Kp = 78.3 at a temperature
106. What is the order of this reaction? ____________________
Time (Min)
0
1
2
3
4
5
6
7
[X] (M)
0.467
0.267
0.187
0.144
0.117
0.099
0.085
0.075
C(g) when Kc = 2.01 at a
Given that the rate constant for the decomposition for Hydrogen Iodide is 1.60 M-1*min-1,
calculate the concentration of X after 12.0 minutes
107. Consider a galvanic cell that uses the following half reactions and answer the following
questions:
2H+(aq) + 2eAl3+(aq) + 3e-
H2(g)
Al(s)
Eo = 0 V
Eo = -.166 V
a) What materials are used for the electrodes? Identify the anode and the cathode.
b) Write a balanced equation for the cell reaction.
c) Calculate the standard cell potential.
d) Calculate the cell potential at 25oC if the ion concentrations are 0.12 M and the partial
pressure of H2 is 12.0 atm.
e) Calculate Go in kJ at 25oC.
f) Calculate pK = -log(K) for the cell reaction at 25oC.
g) Calculate the mass change (grams) of the aluminum electrode after the cell has supplied a
constant current of 15.0 A for 26.0 minutes.
108. How old is a sample of wood whose 14C content is found in 1990 to be 50% that of a living
tree? The half-life for 14C is 5730 years.
109. Use the following mechanism for the following questions:
Step 1:
H2(g) + ICl(g) HI(g) + HCl(g)
Step 2:
HI(g) + ICl(g) I2(g) + HCl(g)
What is the equation of this overall reaction?
What are the reaction intermediates (if any)?
What is the molecularity of the first elementary step?
What is the molecularity of the second elementary step?
110. For each of the following reactions, identify the Bronsted-Lowry acids and bases and the
conjugate acid-base pairs:
a) CN-(aq) + H2O(l)
OH-(aq) + HCN(aq)
b) H2PO4-(aq) + H2O(l)
H3O+(aq) + HPO42-(aq)
c) HPO42-(aq) + H2O(l)
OH-(aq) + H2PO4-(aq)
d) NH4+(aq) + NO2-(aq)
HNO2(aq) + NH3(aq)
111. For the reaction:
2Co3+(aq) + 2Cl-(aq)
2Co2+(aq) + Cl2(g)
Eo = 0.71 V
What is the cell potential at 25oC if the concentrations are [Co3+] = 0.219 M, [Cl-] = 0.122 M,
and [Co2+] = 0.244 M, and the pressure for Cl2 is PCl2 = 3.20 atm?
112. For the vaporization of benzene, Hvap = 30.7 kJ/mol and Svap = 87.0 J/(K*mol)
a) Calculate Ssurr at 73oC
b) Calculate Stotal at 73oC
c) Calculate Ssurr at 80oC
d) Calculate Stotal at 80oC
e) Calculate Ssurr at 87oC
f) Calculate Stotal at 87oC
g) Calculate the normal boiling point of benzene
113. If a saturated solution prepared by dissolving Ag2CO3 in water has [Ag+] = 2.50 x 10-4 M,
what is the value of Ksp for Ag2CO3?
114. a) Uranium-238 decays by alpha emission. What is the mass number of the resulting
element?
b) 23491Th undergoes beta decay. What is the mass number of the resulting element?
c) 23090Th undergoes alpha decay. What is the mass number of the resulting element?
115. Mg(OH)2 is a sparingly soluble salt with a solubility product, Ksp, of 5.61 x 10-11. It is used
to control the pH and provide nutrients in the biological (microbial) treatment of municipal
wastewater streams. What is the ratio of solubility of Mg(OH)2 dissolved in pure H2O to
Mg(OH)2 dissolved in a 0.120 M NaOH solution?
b) What is the pH change of a 0.260 M solution of citric acid (pKa = 4.77) if citrate is added to a
concentration of 0.175 M with no change in volume?
116. a) Calculate the pH of a 0.10 M solution of phenol (Ka = 1.3 x 10-10).
b) Calculate the concentrations of all species present (H3O+, C6H5O-, C6H5OH, and OH-) in a
0.10 M solution of phenol.
c) Calculate the percent dissociation of the above information.
117. What is Kp at 500K for the reaction 2NO(g) Cl2(g)
PCl2 = 0.608 atm, PNOCl = 1.35 atm.
2NOCl(g) when PNO = 0.240 atm,
118. Use the following reaction to answer the following questions:
H2(g) + 2ICl(g)
2HCl(g) + I2(g)
What is the rate law? ______________________________________________
What are the units of the rate constant? ________________________________
119. a) Aspirin (acetylsalicylic acid,C9H8O4) is a weak monoprotic acid. To determine its aciddissociation constant, a student dissolved 2.00 grams of aspirin in 0.600 L of water and measured
the pH. What was the Ka value calculated by the student if the pH of the solution was 2.61?
b) A 0.100 M solution of ethylamine (C2H5NH2) has a pH of 11.87. Calculate the Kb for
ethylamine.
120. Consider the table to answer the following questions:
Reduction Half-Reaction
A+ + e- A
B2+ + 2e- B
C2 + 2e- 2CD3+ + 3e- D
Eo (V)
0.80
0.38
0.17
-1.36
a) Which substance is the strongest oxidizing agent?______________
b) Which is the strongest reducing agent?____________________
c) Which substances can be oxidized by B2+?__________________
d) Which substances can be reduced by D?____________________
e) Write a balanced equation for the overall cell reaction that delivers a voltage of 1.53 V under
standard state conditions.
____________________________________________________________
121. a) How many neutrons must an 5626 Fe nucleus capture to generate an unstable 7326Fe
according to the equation:
56
26Fe
+ ? 10n
73
26Fe
b) How many electrons must the unstable intermediate 7326Fe release to give the 7332Ge nucleus
according to the equation:
73
26Fe
73
32Ge
+ ? 0-1
122. a) What is the pH of the resulting Hydrochloric Acid solution when .65 grams of HCl are
dissolved into water to make 7.5 liters of solution?
b) What is the pH of the solution when .15 grams of NaOH pellets are dissolved in water to make
3.0 Liters of solution?
c) What is the pOH of the solution in Part B?
123. 9. A beaker with 175 mL of acetic acid buffer with a pH of 5.00 is sitting on a bench top.
The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 8.30 mL
of a 0.260 M HCl solution to the beaker. How much of the pH will change? The pKa of acetic
acid is 4.760. (Use a sign if the pH decreased)
124. Calcium chromate, CaCrO4, has a Ksp of 7.1 x 10-4. What happens when calcium and
chromate solutions are mixed to give 0.0200 M Ca2+ and 0.0300 M CrO42-? (Circle the correct
answer)
a) A precipitate forms because Q > Ksp
b) A precipitate forms because Q < Ksp
c) No precipitate forms because Q > Ksp
d) No precipitate forms because Q < Ksp
125. Given the following information answer the following questions.
NH4NO3(s)
Substance
N2O(g)
H2O(g)
NH4NO3(s)
N2O(g) + 2H2O(g)
Gof (kJ/mol)
104.2
-228.6
-184.0
a) Calculate the equilibrium constant Kp at 25oC.
b) Calculate G for the reaction when the partial pressure of each gas is 40 atm.
126. Write balanced nuclear equations for each of the following processes:
a) Beta emission of 157-Eu
b) Electron capture of 126-Ba
c) Alpha emission of 146-Sm
d) Positron emission of 125-Ba
127. Calculate the pH of a solution that is 0.20 M in HF and 0.15 M in NaF.
128. The pH of 0.041 M of HOBr is 5.05
a) What is the equilibrium constant for the dissociation of HOBr?
b) Calculate the value of Ka for the above concentration.
129. Imagine that you are in Chemistry lab and need to make 1.00 L of a solution with a pH of
2.80 and you have in front of you:
100 mL of 7.00 x 10-2 M HCl
100 mL of 5.00 x 10-2 M NaOH
Plenty of DI water
You start to add HCl to a beaker of water when someone asks you a question. When you return
to your dilution, you accidentally grab the wrong cylinder and add some NaOH. Once you
realize your error, you assess the situation. You have 82 mL of HCl 90.0 mL of NaOH left in the
original containers. Assuming the final solution is diluted to 1.00 L, how much more HCl should
you add to achieve the desired pH? (answer should be in mL)
130. Calculate the enthalpy of fusion of naphthalene (C10H8), given that its melting point is
128oC and its entropy of fusion is 47.7 J/(K*mol).
131. a) Predict the sign of the entropy change, So, for each of the following reactions: (+ or -)
a)
b)
c)
d)
e)
f)
Pb2+(aq) + 2Cl-(aq) PbCl2(s) _____________________
CaCO3(s) CaO(s) + CO2(g)_____________________
2NH3(g) N2(g) + 3H2(g)________________________
P4(g) + 5O2(g) P4O10(s)_________________________
C4H8(g) + 6O2(g) 4CO2(g) + 4H2O(g)_______________
I2(s) I2(g)____________________________________
b) Calculate the standard entropy change for the following reaction using the data table from
below: (answer in J/K)
P4(g) + 5O2(g) P4O10(s)
Substance
P4(g)
O2(g)
P4O10(s)
Hof (kJ/mol)
58.9
0
-2984
Gof (kJ/mol)
24.5
0
-2698
So [J/(K*mol)]
279.9
205.0
228.9
132. The standard reduction potential for nickel (II) ion is -.026 V and that of the aluminum (III)
ion is -1.66 V.
a) What is the theoretical cell potential assuming standard conditions?
b) Which metal is the anode?___________________
The cathode? _______________________
133. a) What mass of of Cu(s) is electroplated by running 19.0 A of a current through Cu2+(aq)
solution for 4.00 hours? (Cu2+(aq) + 2e- Cu(s)
Eo = 0.34)
b) How many minutes will it take to electroplate 56.1 grams of gold by running 5.00 A of current
through a solution of Au+(aq)? (Au3+(aq) + 2e- Au+(aq)
Eo = 1.40)
134. The decay constant for plutonium-239 is 2.88 x 10-5 y-1. What is the half life of 238Pu?
135. Calculate the following using Appendix B in the back of textbook for each of the following
reactions:
2SO2(g) + O2(g)
2SO3(g)
Hof = _________________
Sof = _________________
Gof = _________________
N2(g) + 2H2(g)
N2H4(g)
Hof = _________________
Sof = _________________
Gof = _________________
CH3OH(l) + O2(g)
HCO2H(l) + H2O(l)
Hof = _________________
Sof = _________________
Gof = _________________
136. a) What is the pH of a buffer prepared by adding 0.809 mol of the weak acid HA to 0.406
mol of NaA in 2.00 L of solution? The dissociation constant for Ka of HA is 5.66 x 10-7.
b) What is the pH after 0.150 mol of HCl is added to the buffer from Part A? Assume no volume
change on the addition of the acid.
c) What is the pH after 0.195 mol of NaOH is added to the buffer from Part A? Assume no
volume change on the addition of the base.
137. At 25oC, Ka for acid dissociation of aspirin (C9H8O4) is 3.0 x 10-4. Calculate Go for the
reaction:
C9H8O4(aq) + H2O(l)
H3O+(aq) + C9H7O4-(aq)
138. A certain weak acid, HA, with a Ka value of 5.61 x 10-6 , is titrated with NaOH.
a) A solution is made by mixing 7.00mmoles (millimoles) of HA and 1.00 mmoles of the strong
base. What is the resulting pH?
b) More strong base is added until the equivalence point is reached. What is the pH of this
solution at the equivalence point if the total volume is 71.0 mL?
139. Using the So values in Appendix B of your textbook, calculate So at 25oC for each of the
following reactions.
a) 2S(s) + 3O2(g)
2SO3(g)
b) SO3(g) + H2O(l)
c) AgCl(s)
d) NH4NO3(s)
H2SO4(aq)
Ag+(aq) + Cl-(aq)
N2O(g) + 2H2O(g)
140. 12. A mercury battery uses the following electrode half-reactions:
HgO(s) + H2O(l) + 2eZnO(s) + H2O(l) + 2e-
Hg(l) + 2OH-(aq)
Zn(s) + 2OH-(aq)
Eo = 0.098 V
Eo = -1.260 V
a) Write a balanced equation for the overall cell reaction.
b) Calculate Go (in kilojoules) at 25oC for the reaction.
c) Calculate K at 25oC for the reaction.
141. A particular solution of Ca3(PO4)2 has [Ca2+] = [PO43-] = 2.9 x 10-7 M
a) What is the value of Ksp for Ca3(PO4)3?
b) What is [Ca2+] in a saturated solution of Ca3(PO4)3 that has [PO43-] = 1.4 x 10-2 M?
c) What is [PO43-] in a saturated solution of Ca3(PO4)3 that has [Ca2+] = 1.4 x 10-2 M?
142. Consider a galvanic cell based on the reaction below and calculate the cell potential at 25oC
when [Fe2+] = 1.1 M, [Fe3+] = 1.5 x 10-3 M, [Cl-] = 3.0 x 10-3 M, and PCl2 = 0.66 atm.
2Fe2+(aq) + Cl2(g)
2Fe3+(aq) + 2Cl-(aq)
143. Calculate pK = -log(K) at 25oC for each of the following reactions. (Use your textbook to
find Eo values and remember K is the equilibrium constant)
a) 3Cu2+(aq) + 2Cr(s)
3Cu(s) + 2Cr3+(aq)
pK = ______________________
b) Pb(s) + 2H+(aq)
Pb2+(aq) + 2Cr3+(aq)
pK = ______________________
c) Cl2(g) + Sn2+(aq)
Sn4+(aq) + 2Cl-(aq)
pK = ______________________
144. 100 mL of 0.200 M HCl is titrated with 0.250 M NaOH.
a) What is the pH of the solution after 50.0 mL of base has been added?
b) What is the pH at the equivalence point?
145. If 500.0 mL of 0.10 M Ca2+ is mixed with 500.0 mL SO42-, what mass of calcium sulfate
will precipitate? (Ksp for CaSO4 is 2.40 x 10-5), (answer must be in grams)
146. Classify each as acidic, basic, or neutral based on the following table of information:
Acid
HNO3
HOCl
HI
HNO2
HCl
Ka
very large
3.5 x 10-8
very large
4.5 x 10-4
very large
Cation
Fe3+
Ba2+
Na+
NH4+
CH3NH3+
Ka
6.3 x 10-3
very small
very small
5.6 x 10-10
2.7 x 10-11
a) Fe(NO3)3________________
b) Ba(NO3)2________________
c) NaOCl___________________
d) NH4I________________
e) NH4NO2_____________
f) CH3NH3Cl____________