CHEM 10113, Quiz 3
September 28, 2011
Name______________________
(please print)
All equations must be balanced and show phases for full credit. Significant figures count, show charges as appropriate,
and please box your answers!
Periodic Table of the Elements
IA
VIIIA
(1)
(18)
1
1
2
3
4
5
6
7
2
H
IIA
IIIA
IVA
VA
VIA
VIIA
He
1.0080
(2)
(13)
(14)
(15)
(16)
(17)
4.0026
3
4
5
6
7
8
9
10
Li
Be
B
C
N
O
F
Ne
6.9410
9.0122
10.811
12.011
14.007
15.999
18.998
20.179
11
12
13
14
15
16
17
18
Na
Mg
IIB
Al
Si
P
S
Cl
Ar
22.990
24.305
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
26.982
28.086
30.974
32.066
35.453
39.948
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
39.098
40.078
44.956
47.880
50.942
51.996
54.938
55.847
58.933
58.690
63.546
65.380
69.723
72.610
74.922
78.960
79.904
83.800
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
85.468
87.620
88.906
91.224
92.906
95.940
98.907
101.07
102.91
106.42
107.87
112.41
114.82
118.71
121.75
127.60
126.90
131.29
55
56
57
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
132.91
137.33
138.91
178.49
180.95
183.85
186.21
190.20
192.22
195.09
196.97
200.59
204.38
207.20
208.98
208.98
209.99
222.02
87
88
89
104
105
106
107
108
109
110
111
112
IIIB
IVB
VB
VIB
VIIB. . . . . . . . . . VIIIB . . . . . . . . . .IB
Fr
Ra
Ac
Rf
Db
Sg
Bh
Hs
Mt
Ds Uuu Uub
223.02
226.03
227.03
(261)
(262)
(266)
(264)
(270)
(268)
(281)
114
Uug
58
59
60
61
62
63
64
65
66
67
68
69
70
71
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
140.12
140.91
144.24
145.91
150.36
151.97
157.25
158.93
162.50
164.93
167.26
168.93
173.04
174.97
95
96
103
90
91
92
93
94
Th
Pa
U
Np
Pu
232.04
231.04
238.03
237.05
244.06
Am Cm
243.06
247.07
97
98
99
100
101
102
Bk
Cf
Es
Fm
Md
No
Lr
247.07
242.06
252.08
257.10
258.10
259.10
260.11
1. (6 points) For the reaction between lead(II) nitrate and potassium phosphate, write the balanced molecular
equation, ionic equation, and net ionic equation. Identify the precipitate and the spectator ions.
a) molecular equation
3 Pb(NO3)2(aq) + 2 K3PO4(aq)  Pb3(PO4)2(s) + 6 KNO3(aq)
b) ionic equation
3 Pb2+(aq) + 6 NO3–(aq) + 6 K+(aq) + 2 PO43– (aq)  Pb3(PO4)2(s) + 6 K+(aq) + 6 NO3–(aq)
Spectator ions are the potassium and nitrate, and precipitate is the lead(II) phosphate.
c) net ionic equation
3 Pb2+(aq) + 2 PO43–(aq)  Pb3(PO4)2(s)
2. (2 points) You are given a solution that is 0.150 M in CuSO4. If you dilute 6.00 mL of this solution to 10.0
mL, what is the concentration of the new solution?
(0.150 M)(6.00 mL) = (10.0 mL)x
x = 0.0900 M
1
3. (4 points) SHOW ALL WORK. You have 0.954 g of an unknown diprotic acid. If 36.04 mL of 0.509 M
NaOH is required to titrate the acid to the equivalence point, what is the formula mass of the acid?
H2A(aq) + 2 NaOH(aq)  2 H2O(l) + Na2A(aq)
36.04 mL NaOH soln x (0.509 mol NaOH/1000 mL NaOH soln) x (1 mol H2A/2 mol NaOH) = 9.17218 x 10–3
mol H2A
0.954 g H2A/9.17218 x 10–3 mol H2A = 104 g/mol H2A
4. (6 points) For each of the following reactions, write the balanced molecular equation, or NR if there is no
reaction.
2
HCl(aq)  2 H2O(l) + BaCl2(aq)
a)
Ba(OH)2(aq) +
b)
MgCO3(aq) + 2 HCl(aq)  H2O(l) + CO2(g) + MgCl2(aq)
c)
MnCl2(aq) +
Na2S(aq)  2 NaCl(aq) + MnS(s)
5. (4 points) SHOW ALL WORK. For the following balanced reaction,
Mg(C2H3O2)2(aq) + 2 KOH(aq)  Mg(OH)2(s) + KC2H3O2(aq)
if 34.6 mL of 1.80 M KOH is fully consumed, and the final volume is 45.0 mL, what is the expected
concentration of KC2H3O2?
34.6 mL KOH soln x (1.80 mol KOH/1000 mL KOH soln) x (1 mol KC2H3O2/2 mol KOH) = 0.03114 mol
KC2H3O2
0.03114 mol KC2H3O2/0.0450 L soln = 0.692 M KC2H3O2
6. (3 points) For the following reaction, assign oxidation numbers to all atoms (both reactants and products).
Clearly show which substance is oxidized and which is reduced.
3 Cu(s) + 8 HNO3(aq)  3 Cu(NO3)2(aq) + 2 NO(g) + 4 H2O(l)
Cu: 0 This one gets oxidized.
HNO3: H +1, N +5, O –2 This one gets reduced (the nitrogen).
Cu(NO3)2: Cu +2, N +5, O –2
NO: N +2, O –2
H2O: H +1, O –2
2
CHEM 10113, Quiz 3
September 28, 2011
Name______________________
(please print)
All equations must be balanced and show phases for full credit. Significant figures count, show charges as appropriate,
and please box your answers!
Periodic Table of the Elements
IA
VIIIA
(1)
(18)
1
1
2
3
4
5
6
7
2
H
IIA
IIIA
IVA
VA
VIA
VIIA
He
1.0080
(2)
(13)
(14)
(15)
(16)
(17)
4.0026
3
4
5
6
7
8
9
10
Li
Be
B
C
N
O
F
Ne
6.9410
9.0122
10.811
12.011
14.007
15.999
18.998
20.179
11
12
13
14
15
16
17
18
Na
Mg
IIB
Al
Si
P
S
Cl
Ar
22.990
24.305
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
26.982
28.086
30.974
32.066
35.453
39.948
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
39.098
40.078
44.956
47.880
50.942
51.996
54.938
55.847
58.933
58.690
63.546
65.380
69.723
72.610
74.922
78.960
79.904
83.800
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
85.468
87.620
88.906
91.224
92.906
95.940
98.907
101.07
102.91
106.42
107.87
112.41
114.82
118.71
121.75
127.60
126.90
131.29
55
56
57
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
132.91
137.33
138.91
178.49
180.95
183.85
186.21
190.20
192.22
195.09
196.97
200.59
204.38
207.20
208.98
208.98
209.99
222.02
87
88
89
104
105
106
107
108
109
110
111
112
IIIB
IVB
VB
VIB
VIIB. . . . . . . . . . VIIIB . . . . . . . . . .IB
Fr
Ra
Ac
Rf
Db
Sg
Bh
Hs
Mt
Ds Uuu Uub
223.02
226.03
227.03
(261)
(262)
(266)
(264)
(270)
(268)
(281)
114
Uug
58
59
60
61
62
63
64
65
66
67
68
69
70
71
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
140.12
140.91
144.24
145.91
150.36
151.97
157.25
158.93
162.50
164.93
167.26
168.93
173.04
174.97
95
96
103
90
91
92
93
94
Th
Pa
U
Np
Pu
232.04
231.04
238.03
237.05
244.06
Am Cm
243.06
247.07
97
98
99
100
101
102
Bk
Cf
Es
Fm
Md
No
Lr
247.07
242.06
252.08
257.10
258.10
259.10
260.11
1. (6 points) For the reaction between lead(II) nitrate and ammonium sulfide, write the balanced molecular
equation, ionic equation, and net ionic equation. Identify the precipitate and the spectator ions.
a) molecular equation
Pb(NO3)2(aq) + (NH4)2S(aq)  Pb2S(s) + 2 NH4NO3(aq)
b) ionic equation
Pb2+(aq) + 2 NO3–(aq) + 2 NH4+(aq) + S2–(aq)  Pb2S(s) + 2 NH4+(aq) + 2 NO3–(aq)
Precipitate is lead(II) sulfide and the spectator ions are ammonium and nitrate ions.
c) net ionic equation
Pb2+(aq) + S2–(aq)  Pb2S(s)
2. (2 points) You are given a solution that is 0.250 M in CuSO4. If you dilute 8.00 mL of this solution to 15.0
mL, what is the concentration of the new solution?
(0.250 M)(8.00 mL) = (15.0 mL)x
x = 0.133 M
3
3. (4 points) SHOW ALL WORK. You have 1.024 g of an unknown diprotic acid. If 26.04 mL of 0.722 M
NaOH is required to titrate the acid to the equivalence point, what is the formula mass of the acid?
H2A(aq) + 2 NaOH(aq)  2 H2O(l) + Na2A(aq)
26.04 mL NaOH soln x (0.722 mol NaOH/1000 mL NaOH soln) x (1 mol H2A/2 mol NaOH) = 9.40044 x 10–3
mol H2A
1.024 g H2A/9.40044 x 10–3 mol H2A = 109 g/mol H2A
4. (6 points) For each of the following reactions, write the balanced molecular equation, or NR if there is no
reaction.
a)
2
HNO3(aq) +
CoCO3(s)  H2O(l) + CO2(g) + Co(NO3)2(aq)
b)
Pb(NO3)2(aq) + 2 HCl(aq)  PbCl2(s) + 2 HNO3(aq)
c)
K2CO3(aq) +
ZnCl2(aq)  2 KCl(aq) + ZnCO3(s)
5. (4 points) SHOW ALL WORK. For the following balanced reaction,
Mg(C2H3O2)2(aq) + 2 KOH(aq)  Mg(OH)2(s) + KC2H3O2(aq)
if 54.6 mL of 7.54 M KOH is is fully consumed, and the final volume is 75.0 mL, what is the expected
concentration of KC2H3O2?
54.6 mL KOH soln x (7.54 mol KOH/1000 mL KOH soln) x (1 mol KC2H3O2/2 mol KOH) = 0.205842 mol
KC2H3O2
0.205842 mol KC2H3O2/0.0750 L soln = 2.74 M KC2H3O2
6. (3 points) For the following reaction, assign oxidation numbers to all atoms (both reactants and products).
Clearly show which substance is oxidized and which is reduced.
8 H+(aq) + 3 SO32–(aq) + Cr2O72–(aq)  3 SO42–(aq) + 2 Cr3+(aq) + 4 H2O(l)
H+: H +1
SO32–: S +4, O –2 The sulfur gets oxidized.
Cr2O72–: Cr +6, O –2. The chromium gets reduced.
SO42–: S +6, O –2
Cr3+: Cr +3
H2O: H +1, O –2
4
CHEM 10113, Quiz 3
September 28, 2011
Name______________________
(please print)
All equations must be balanced and show phases for full credit. Significant figures count, show charges as appropriate,
and please box your answers!
Periodic Table of the Elements
IA
VIIIA
(1)
(18)
1
1
2
3
4
5
6
7
2
H
IIA
IIIA
IVA
VA
VIA
VIIA
He
1.0080
(2)
(13)
(14)
(15)
(16)
(17)
4.0026
3
4
5
6
7
8
9
10
Li
Be
B
C
N
O
F
Ne
6.9410
9.0122
10.811
12.011
14.007
15.999
18.998
20.179
11
12
13
14
15
16
17
18
Na
Mg
IIB
Al
Si
P
S
Cl
Ar
22.990
24.305
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
(12)
26.982
28.086
30.974
32.066
35.453
39.948
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
K
Ca
Sc
Ti
V
Cr
Mn
Fe
Co
Ni
Cu
Zn
Ga
Ge
As
Se
Br
Kr
39.098
40.078
44.956
47.880
50.942
51.996
54.938
55.847
58.933
58.690
63.546
65.380
69.723
72.610
74.922
78.960
79.904
83.800
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
Rb
Sr
Y
Zr
Nb
Mo
Tc
Ru
Rh
Pd
Ag
Cd
In
Sn
Sb
Te
I
Xe
85.468
87.620
88.906
91.224
92.906
95.940
98.907
101.07
102.91
106.42
107.87
112.41
114.82
118.71
121.75
127.60
126.90
131.29
55
56
57
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
Cs
Ba
La
Hf
Ta
W
Re
Os
Ir
Pt
Au
Hg
Tl
Pb
Bi
Po
At
Rn
132.91
137.33
138.91
178.49
180.95
183.85
186.21
190.20
192.22
195.09
196.97
200.59
204.38
207.20
208.98
208.98
209.99
222.02
87
88
89
104
105
106
107
108
109
110
111
112
IIIB
IVB
VB
VIB
VIIB. . . . . . . . . . VIIIB . . . . . . . . . .IB
Fr
Ra
Ac
Rf
Db
Sg
Bh
Hs
Mt
Ds Uuu Uub
223.02
226.03
227.03
(261)
(262)
(266)
(264)
(270)
(268)
(281)
114
Uug
58
59
60
61
62
63
64
65
66
67
68
69
70
71
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
Lu
140.12
140.91
144.24
145.91
150.36
151.97
157.25
158.93
162.50
164.93
167.26
168.93
173.04
174.97
95
96
103
90
91
92
93
94
Th
Pa
U
Np
Pu
232.04
231.04
238.03
237.05
244.06
Am Cm
243.06
247.07
97
98
99
100
101
102
Bk
Cf
Es
Fm
Md
No
Lr
247.07
242.06
252.08
257.10
258.10
259.10
260.11
1. (6 points) For the reaction between sodium carbonate and copper(II) chloride, write the balanced molecular
equation, ionic equation, and net ionic equation. Identify the precipitate and the spectator ions.
a) molecular equation
Na2CO3(aq) + CuCl2(aq)  CuCO3(s) + 2 NaCl(aq)
b) ionic equation
2 Na+(aq) + CO32–(aq) + Cu2+(aq) + 2 Cl–(aq)  CuCO3(s) + 2 Na+(aq) + 2 Cl–(aq)
Precipitate is copper(II) carbonate, and spectator ions are sodium and chloride.
c) net ionic equation
CO32–(aq) + Cu2+(aq)  CuCO3(s)
2. (2 points) You are given a solution that is 0.350 M in CuSO4. If you dilute 4.00 mL of this solution to 20.0
mL, what is the concentration of the new solution?
(0.350 M)(4.00 mL) = (20.0 mL)x
x = 0.0700 M
5
3. (4 points) SHOW ALL WORK. You have 0.853 g of an unknown triprotic acid. If 55.04 mL of 0.609 M
NaOH is required to titrate the acid to the equivalence point, what is the formula mass of the acid?
H3A(aq) + 3 NaOH(aq)  3 H2O(l) + Na3A(aq)
55.04 mL NaOH soln x (0.609 mol NaOH/1000 mL NaOH soln) x (1 mol H3A/3 mol NaOH) = 0.01117312
mol H3A
0.853 g H3A/0.01117312 mol H3A = 76.3 g/mol H3A
4. (6 points) For each of the following reactions, write the balanced molecular equation, or NR if there is no
reaction.
Cu(NO3)2(aq)  2 KNO3(aq) + CuCO3(s)
a)
K2CO3(aq) +
b)
Fe(OH)3(s) +
3 HNO3(aq)  3 H2O(l) + Fe(NO3)3(aq)
c)
FeSO3(s) + 2
HNO3(aq)  H2O(l) + SO2(g) + Fe(NO3)2(aq)
5. (4 points) SHOW ALL WORK. For the following balanced reaction,
Mg(C2H3O2)2(aq) + 2 KOH(aq)  Mg(OH)2(s) + KC2H3O2(aq)
if 42.4 mL of 2.10 M KOH is fully consumed, and the final volume is 57.5 mL, what is the expected
concentration of KC2H3O2?
42.4 mL KOH soln x (2.10 mol KOH/1000 mL KOH soln) x (1 mol KC2H3O2/2 mol KOH) = 0.04452 mol
KC2H3O2
0.04452 mol KC2H3O2/0.0575 L soln = 0.774 M KC2H3O2
6. (3 points) For the following reaction, assign oxidation numbers to all atoms (both reactants and products).
Clearly show which substance is oxidized and which is reduced.
5 H2O(l) + 4 Cl2(g) + S2O32–(aq)  2 SO42–(aq) + 8 Cl–(aq) + 10 H+(aq)
H2O: H +1, O –2
Cl2: Cl 0. The Cl gets reduced.
S2O32–: S +2, O –2. The S gets oxidized.
SO42–: S +6, O –2
Cl–: Cl –1
H+: H +1
6