EXAM IIK CH 107
PAGE 1 of 13
NAME:___________________________
EXAM IIK
March 2, 2004
CH 107
DIRECTIONS
• There is only one correct answer to each question. Any questions for which more than one response has been selected will not be
counted
• Your score is based solely on the number of questions you answer correctly. It is to your advantage to answer every question.
• The best strategy is to arrive at your own answer to a question before looking at the choices. Otherwise, you may be misled by
plausible, but incorrect, responses.
IF YOU SELECT THE ANSWER “NONE OF THE ABOVE”, WRITE YOUR CALCULATIONS AND CORRECT ANSWER
DOWN NEXT TO IT.
TAKE A DEEP BREATH AND LET YOUR EYES FOCUS.
RELAX YOUR SHOULDERS
YOU KNOW MORE THAN YOU THINK YOU DO!
W
WH
HEEN
N IIN
ND
DO
OU
UB
BT
T,, C
CO
ON
NV
VEER
RT
TT
TO
OM
MO
OLLEESS!!
PAGE 1 of 13
POINTS:_______
EXAM IIK CH 107
PAGE 2 of 13
NAME:___________________________
INORGANIC NOMENCLATURE:
1. Name, by IUPAC rules, the following compounds:
a. H2SO4
___Sulfuric acid_______________________________
b. NH4NO3
___Ammonium nitrate_______________________________
c. CH3COOK (KAc)
d. Ba(OH)2
e.
HBrO
_Potassium acetate_____________________________
___Barium hydroxide___________________________________
___HYPOBROMOUS ACID!!!!___________________
5 pts: ____
2. Give formulae for the following compounds:
a. Ammonia: _NH3________________________________
b. Hydronium ion: ___H3O+_______________________
c. Nitric acid: ____HNO3___________________________
d. Acetic acid : ___CH3COOH____________________________
e. Chloric acid: ____HClO3__________________________
BONUS: Name and give the formula for a STRONG ACID
Hydrochloric acid
Hydrobromic acid
Hydroiodic acid
Nitric acid
Sulfuric acid
Perchloric acid
PAGE 2 of 13
HCl
HBr
HI
HNO3
H2SO4
HClO4
POINTS:_______
5 pts: ____
EXAM IIK CH 107
PAGE 3 of 13
NAME:___________________________
3-4. SHORT ANSWER SECTION: WRITE YOUR RESPONSES LEGIBLY (IF I CAN’T READ IT I
CAN”T SCORE IT)! REMEMBER CHARGES!
a. Write the balanced net ionic equation for the reaction of water with water.
H2O(l) + H2O(l) ⇆ H3O+(aq) + OH-(aq)
b. Write the balanced net ionic equation for the reaction of HCl. and water.
HCl (aq) + H2O(l) ⇆ H3O+(aq) + Cl-
(aq)
OR H+(aq) + H2O(l) ⇆ H3O+(aq)
c. Write the balanced net ionic equation for the reaction of NaOH with HCl
Na+ (aq) + OH- (aq) + H+(aq) + Cl-(aq) ⇆ H2O(l) + Na+(aq) + Cl- (aq)
OH- (aq) + H+(aq) ⇆ H2O(l) OR OH- (aq) + H3O+(aq) ⇆ 2H2O(l)
d. Write the balanced net ionic equation for the reaction of acetic acid and water.
CH3COOH(aq) + H2O(l) ⇆ CH3COO-(aq) + H3O+
e. Write the balanced net ionic equation for the reaction of sodium acetate with water.
Na+(aq) +
CH3COO-(aq) + H2O(l) ⇆ CH3COOH(aq) + OH-(aq)
f. Write the balanced net ionic equation for the reaction of ammonia with water.
NH3(aq) + H2O(l) ⇆ NH4+(aq) + OH-(aq)
g. Write the balanced net ionic equation for the reaction of ammonium chloride with water.
NH4+(aq) + Cl-(aq) + H2O(l) ⇆ NH3(aq) + H3O+
h. Write the balanced net ionic equation for the reaction of nitric acid with potassium
hydroxide.
H+(aq) + NO3-(aq) + K+ (aq) + OH- (aq) ⇆ H2O(l) + K+(aq) + NO3-(aq)
H+(aq) + OH- (aq) ⇆ H2O(l) OR H3O+(aq) + OH- (aq) ⇆ 2H2O(l)
i. Write the balanced net ionic equation for the reaction of sodium fluoride with sulfuric acid.
2Na+(aq) + 2F-(aq) + 2H+(aq) + SO42-(aq) ⇆ 2HF(aq)
+
SO42-(aq) + 2Na+(aq)
H+(aq) + F-(aq) ⇆ HF(aq) OR H3O+(aq) + F-(aq) ⇆ HF(aq) + H2O(l)
j. Write the balanced net ionic equation for the reaction of acetic acid with sodium
hydroxide..
CH3COOH(aq) + Na+(aq) + OH-(aq) ⇆ CH3COO-(aq) + Na+(aq)- + H2O(l)
CH3COOH(aq) + OH-(aq) ⇆ CH3COO-(aq)
PAGE 3 of 13
+
H2O(l)
POINTS:_______
EXAM IIK CH 107
PAGE 4 of 13
NAME:___________________________
5. In this reaction, which substances are bases according to the Brønsted–Lowry definition?
H3C
H 3C
H
H3C
+ OH-
H 2C
H 3C
O
N+
:N
CH
H 2C
O
CH
O
CH
H 2C
CH
H 2C
+ H2O
H 2C
O
CH
CH
CH 2
H 2C
CH 2
CH
CH
HC
C
O
HC
C
HC
C
C
HC
HC
O
C
HC
CocaineNH+
+ OH-
CH
6. The conjugate acid of CH3NH2 is
(B)
-
CH3NH
-
:CH2NH2
CH3NH3+ Cl-
(C)
(D)
All of the above
7. What is the pH of 50.00 μL of 5.11 x 10-4 M HClO4?
A
B
5.11 x 10-4
3.29
C
D
E
1.59
7.59
None of the above
8.
A
B
C
D
E
HClO4 is a strong acid
{H3O+} = 5.11 x 10-4 M
pH = -log(5.11 x 10-4) = B
The pH of 50.00 μL of 8.75 x 10-5 M Ba(OH)2 solution at 25 °C is
Ba(OH)2 is a strong base
{OH-} = 2 x 8.75 x 10-5 M
pOH = -log(1.75 x 10-4) = 3.76
pH = pKw – pOH = 14 – 3.76 = C
3.76
4.06
10.2
2.36
None of the above
BONUS: Calculate the pH of 14 M HNO3 .
{H3O+} = 14 M
pH = -log(14) = -1.15
PAGE 4 of 13
O
CocaineN: + H2O
The bases are:
A. CocaineNH+ & H2O are both bases in this reaction;
B. CocaineNH+ and OH- are both bases in this reaction;
C. OH- and H2O are both bases in this reaction;
D. CocaineN: & OH- are both bases in this reaction.
(A)
C
O
CH
POINTS:_______
EXAM IIK CH 107
PAGE 5 of 13
NAME:___________________________
[H3O+][OH-] = Kw = 10-14
9. Calculate the [OH-] in pure water.
A
B
C
D
E
in pure water [H3O+] = [OH-]
1.0 x 10-14 M
1. 0 x 10-7 M
7.00
14.00
None of the above
[OH-] = 10-7 M
10. Calculate the pH of 500 L of 0.0350 M lactic acid (LacCOOH), a weak acid produced when your
muscles go anaerobic during burst of exercise.
pKa[LacCOOH] = 3.80
A
B
C
D
E
F
1.46
1.92
2.63
1.17
4.15
None of the above
In a solution of a weak acid:
pH ≅ pKa + p[HA] = 3.80 –log(0.035) = C
2
2
11. Calculate the pH of 0.0040 M potassium lactate, LacCOO:-K+, a weak base.
pKa[LacCOOH] =
A
B
C
D
E
F
3.80.
2.40
3.10
6.30
12.6
7.70
None of the above
In a solution of a weak base:
pKb = pKw – pKa = 14 – 3.8 = 10.2
pOH ≅ pKb + p[A:-] = 10.2 –log(0.004) = 6.30
2
2
pH = pKw = pOH = 14 – 6.3 = E
12. Calculate the pH of a mixture of 0.015000 M Lactic acid, LacCOOH, and 0.05500 M Sodium
lactate LacCOO:- Na+.
pKa[LacCOOH] = 3.80 .
A
B
C
4.36
1.15
4.95
D
E
F
3.24
3.67
None of the above
In a mixture of weak acid & conj. weak base:
pH = pKa + log([A:-]/[HA])
= 3.80 + log(0.0055/0.015) = A
BONUS: The normal pH of the human bloodstream is 7.4. During severe metabolic acidosis, the
pH drops to 7.1. During metabolic acidosis, which is true?
(A) the [H3O+] increases (B) the [H3O+] decreases (C) the [H3O+] remains constant
PAGE 5 of 13
POINTS:_______
EXAM IIK CH 107
PAGE 6 of 13
NAME:___________________________
13. The pH of a ripe orange is 4.34. The [OH-] is:
A
B
C
D
E
0.637
M
9.66
M
-5
4.57 x 10
M
2.19 x 10-10 M
None of the above
pOH = pKw - pH = 14 – 4.34 = 9.66
[OH-] = 10-9.66 = D
14. Consider the amino acid tyrosine:
O
O
H2N
CH
C
OH
H2N
CH
C
OH
CH 2
CH 2
pK
10.07
pKaa ==10.07
:O:-
OH
Calculate the ratio of deprotonated (-:O:-) to protonated (-OH-) tyrosine at pH 8.05.
A
B
C
D
E
105/1
0.00955/1
0.803/1
1.25/1
None of the above
In a mixture of weak acid & conj. weak base:
pH = pKa + log([O:-]/[-OH])
8.05 = 10.07 + log(-O-/-OH)
-2.02 = log(-O-/-OH)
10-2.02 = (-O-/-OH) = B
15. NH4NO3
(A) Is a strong acid
(B) Is a weak acid NH4+
(C) Is a strong base
(D) Is a weak base
BONUS: Ph (Upper case P, lower case h) is the abbreviation for:
(A) “Phenyl group” (B) -log[H3O+]
PAGE 6 of 13
POINTS:_______
EXAM IIK CH 107
PAGE 7 of 13
NAME:___________________________
THE TITRATION CURVE SHOWN BELOW HAS DATA FOR THE NEXT THREE (3) QUESTIONS:
Potentiometric titration of 5.5000 g of Troupialic Acid (HTr) by 0.0987 M NaOH
12.5
12
11.5
11
10.5
10
pH
9.5
9
8.5
Equivalence
point
8
7.5
7
6.5
pH = pKa
6
5.5
5
0
10
20
30
40
50
60
70
80
90 100 110 120 130 140 150 160 170 180 190 200 210 220 230 240 250
mL 0.0987 M NaOH added
16 According to the data, the pKa of Troupialic acid (HTr) is close to:
(A) 12.6
(B) 11.0
(C) 8.05
(D) 5.50
(E) None of the above
17. According to the data, the end point of the titration is:
(A) 220.0 mL
(B) 200.0 mL
(C) 100.0 mL (D) 50.00 mL (E) 0.00 mL
18. The point in the titration where the [Troupialic acid (HTr)] = [sodium troupialidate:- (Tr:-)] is:
(A) 220.0 mL
(B) 200.0 mL
(C) 100.0 mL (D) 50.00 mL (E) 0.00 mL
19. Given that: HTr + OH-  Tr:- + H2O, Calculate the molecular weight of Troupialic acid:
(A)
(B)
(C)
(D)
(E)
20.0 g/mol
55.72 g/mol mL
139.3 g/mol mL
278.6 g/mol
None of the above
200 mL NaOH (1 L/1000 mL)(0.0987 mol NaOH/L)(1 HTr/1 OH-) = 0.01974 mol HTr
5.5000 g HTr/ 0.01974 mol HTr = D
BONUS: Vinegar is pure acetic acid in water. If the pH of vinegar is 2.42, calculate the [CH 3COOH]
pKa(CH3COOH) = 4.75
pH = pKa + p[HAc] 2.42 = 4.75 – log[HAc];
4.84 -4.75 = -log[HAc] = 0.0900; log[HAc] = -0.0900; [HAc] = 10-0.09
2
2
= 0.81 M
PAGE 7 of 13
POINTS:_______
EXAM IIK CH 107
PAGE 8 of 13
NAME:___________________________
Use the table of pKa’s on the LAST PAGE for the next three (3) questions:
20. Which is the WEAKEST ACID?
A
B
C
D
E
F
Benzoic acid
Acetylene
Hydroiodic acid
Trifluoroacetic acid
Phenol
None of the above, they are all equally weak
21. Calculate the pKb of sodium phenoxide
O- Na+
9.9
4.1
7.94 x 10-5
1.26 x 10-10
None of the above
A
B
C
D
E
Sodium phenoxide is the conjugate
weak base of phenol
pKb = pKw – pKa = 14 – 9.9 = B
Sodium phenoxide
22. Which of the weak acids listed (see back page) has the STRONGEST conjugate weak base?
A
B
C
D
E
F
Benzoic acid
Acetylene
Hydroiodic acid
Trifluoroacetic acid
Phenol
None of the above, they are all equally weak
BONUS: Calculate the pH of 0.10 M acetic acid (HAc) (pKa = 4.85 at 25oC)!
pH ≅ pKa + p[HAc] = 4.85 –log(0.10)
2
2
PAGE 8 of 13
= 2.92
POINTS:_______
EXAM IIK CH 107
PAGE 9 of 13
NAME:___________________________
Which acid is STRONGEST:
A.
B.
C.
D.
E.
CH3COOH, acetic acid
CFH2COOH, fluoroacetic acid
CF2HCOOH, difluoroacetic acid
CF3COOH, trifluoroacetic acid
All are of equal strength
22. Which acid is the WEAKEST:
A.
B.
C.
D.
E.
BrOH, hypobromous acid
BrO2H, bromous acid
BrO3H, bromic acid
BrO4H, perbromic acid
All are of equal strength
23. Which acid is NOT a strong acid?
A. HBr
B. H2SO4
C. HNO3
D. HF
E. HClO4
24. Which of these is a BASE?
A. NaOH
B. :NH3
C. CH3NH
.. 2
D. CH3CH2COO: - Na+
E. NaF
F. All of the above
G. None of the above
25. Write the equilibrium expression and the numerical value for the reaction of water with water.
H2O(l) + H2O(l) ⇆ H3O+(aq) + OH-(aq)
[H3O+][OH-] = Kw = 10-14
BONUS: Name and give the formula for a STRONG BASE. NaOH, KOH, LiOH, Ba(OH)2,
NaNH2, CH3ONa
PAGE 9 of 13
POINTS:_______
EXAM IIK CH 107
PAGE 10 of 13
NAME:___________________________
26. An amphoteric compound:
A.
B.
C.
D.
Can act as both an acid and a base. H2O is an example.
Is a pure weak acid. HF is an example.
Is a pure weak base. NaF is an example;
Does no appreciable acid/base chemistry. NaCl is an example
27. The voltage output of a pH meter
A.
B.
C.
D.
Is directly proportional to the [OH-]
Is directly proportional to the [H3O+]
Is directly proportional to the log[H3O+]
Is unrelated to either [OH-] or [H3O+]
KLAQUE’S BONUS: WHAT IS THE pH OF 1 x 10-8 M HCl?
At low concentrations of acid, you have to remember that water produces H3O+ too.
H3O+ from H2O: ≅ 1 x 10-7 M
H3O+ from HCl: = 1 x 10-8 M
H3O+ total:
≅ 1.1 x 10-7 M
pH ≅ 6.96
PAGE 10 of 13
POINTS:_______
EXAM IIK CH 107
PAGE 11 of 13
NAME:___________________________
PERIODIC TABLE OF THE ELEMENTS
1A
8A
1
H
2
He
3
Li
2A
4
Be
3A
5
B
4A
6
C
5A
7
N
6A
8
O
7A
9
F
6.941
9.012
10.81
12.01
14.01
16.00
19.00
20.18
11
Na
12
Mg
5B
6B
7B
15
P
16
S
17
Cl
18
Ar
24.31
4B
14
Si
22.99
3B
13
Al
19
K
20
Ca
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
39.10
40.08
44.96
47.88
50.94
52.00
54.94
55.85
37
Rb
38
Sr
39
Y
40
Zr
41
Nb
42
Mo
43
Tc
44
Ru
85.47
87.62
88.91
91.22
92.91
95.94
(98)
55
Cs
56
Ba
57
La
72
Hf
73
Ta
74
W
75
Re
132.9
137.3
138.9
178.5
181.0
183.8
186.2
87
Fr
88
Ra
89
Ac
(223)
226.0
227.0
104 105 106 107 108 109
Un Un Un Uns Uno Une
(262)
(265)
(266)
q
p
h
1.008
8B
10
Ne
1B
2B
26.98
28.09
30.97
32.07
35.45
39.95
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
36
Kr
58.93
58.69
63.55
65.39
69.72
72.61
74.92
78.96
79.90
83.80
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
54
Xe
101.1
102.9
106.4
107.9
112.4
114.8
118.7
121.8
127.6
126.9
131.3
76
Os
77
Ir
78
Pt
79
Au
80
Hg
81
Tl
82
Pb
83
Bi
84
Po
85
At
86
Rn
190.2
192.2
195.1
197.0
200.6
204.4
207.2
209.0
(209)
(210)
(222)
68
Er
69
Tm
70
Yb
71
Lu
168.9
173.0
175.0
(261)
(262)
(263)
58
Ce
59
Pr
60
Nd
61
Pm
62
Sm
63
Eu
64
Gd
65
Tb
66
Dy
67
Ho
140.1
140.9
144.2
(145)
150.4
152.0
157.3
158.9
162.5
164.9
167.3
90
Th
91
Pa
92
U
93
Np
94
Pu
95 96
Am Cm
97
Bk
98
Cf
99
Es
100 101 102 103
Fm Md No Lr
232.0
231.0
238.0
237.0
(244)
(243)
(247)
(251)
(252)
(257)
PAGE 11 of 13
4.003
(247)
POINTS:_______
(258)
(259)
(260)
EXAM IIK CH 107
PAGE 12 of 13
NAME:___________________________
SPECIAL UNITS & CONVERSION FACTORS
Acceleration due to gravity (g)
Avogadro’s number
Bohr radius
Boltzmann’s constant
Electronic charge-to-mass ratio
Elementary charge
Faraday constant
Gravitational constant (Universal)
Mass of an electron
Mass of a neutron
Mass of a proton
Molar volume of an ideal gas @ STP
Permittivity of vacuum
Planck’s constant
Rydberg constant
Speed of light in vacuo
Universal gas constant
PAGE 12 of 13
g
No
ao
kB
-e/me
e
F
G
me
Mn
Mp
Vm
εo
h
R∞
c
R
9.80665 m/sec2
6.022x 1023 particles/mol
0.529177249 x 10-10 m
1.38 x 10-23 J/K
1.759 x 1011 C/kg
1.602 x 10-19 C
9.648 x 104 C/mol
6.673 x 10-11 m3/kg sec2
9.109 x 10-31 kg
1.675 x 10-27 kg
1.673 x 10-27 kg
22.414 L/mol
8.854 x 10-12 C2/N m2
6.6265 x 10-27 J sec
2.180 x 10-18 J
2.998 x 108 m/sec
8.3145 J/mol K
0.082058 L atm/K mol
POINTS:_______
EXAM IIK CH 107
PAGE 13 of 13
NAME:___________________________
From E. P. Serjeant and B. Dempsey (eds.), Ionization Constants of Organic Acids in
Solution, IUPAC Chemical Data Series No. 23, Pergamon Press, Oxford, UK, 1979.
TABLE OF pKa’s:
pKa
Acid Name
-10
Hydroiodic acid
0.5
Trifluoroacetic
acid
4.2
Benzoic acid
4.6
Anilinium ion
4.8
Acetic acid
6.4
Carbonic acid
Acid Structure/ Base Structure
Base name
Iodide ion
trifluoroacetate
ion
benzoate ion
Aniline
acetate ion
7
bicarbonate
ion
Hydrogen
sulfide
bisulfide ion
ammonia
9.3
Ammonium ion
9.3
Hydrogen
cyanide
Cyanide ion
Phenoxide ion
9.9
Phenol
10.8
Ethylammonium
ion
Ethyl amine
16
Ethanol
Ethoxide ion
25
Acetylene
Acetylide ion
Methide ion
approx.
Methane
60
PAGE 13 of 13
POINTS:_______