NAME:____________________________
Fall 2014
INSTRUCTIONS:
Student Number:______________________
Chemistry 1000 Midterm #2C
____/ 68 marks
1) Please read over the test carefully before beginning. You should have
6 pages of questions and a formula/periodic table sheet.
2) If your work is not legible, it will be given a mark of zero.
3) Marks will be deducted for incorrect information added to an otherwise
correct answer.
4) Marks will be deducted for improper use of significant figures and for
missing or incorrect units.
5) Show your work for all calculations. Answers without supporting
calculations will not be given full credit.
6) You may use a calculator.
7) You have 90 minutes to complete this test.
Confidentiality Agreement:
I agree not to discuss (or in any other way divulge) the contents of this exam until after 7:30 pm
Mountain Time on Thursday, November 6th, 2014. I understand that breaking this agreement
would constitute academic misconduct, a serious offense with serious consequences. The
minimum punishment would be a mark of 0/68 on this exam and removal of the “overwrite
midterm mark with final exam mark” option for my grade in this course; the maximum punishment
would include expulsion from this university.
Signature: ___________________________
Course: CHEM 1000 (General Chemistry I)
Semester: Fall 2014
The University of Lethbridge
Date: _____________________________
Question Breakdown
Spelling matters!
Fluorine = F
Flourine =
Fluorene = C13H10
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
Q9
/ 11
/ 13
/8
/4
/ 15
/4
/3
/6
/4
Total
/ 68
NAME:____________________________
Student Number:______________________
1.
[11 marks]
(a)
Write the symbols for the missing elements in the periodic table below (elements 14-15,
elements 19-30, and the first four elements of group 18).
(b)
Give the names for each of the following elements:
i.
Z = 12
ii.
Z = 16
iii.
Z = 18
iv.
Z = 29
Partial Periodic Table (copied from data sheet)
1
18
1.0079
H
2
13
14
15
16
17
9.0122
10.811
12.011
14.0067
15.9994
18.9984
Be
B
C
N
O
5
26.9815
6
28.0855
7
30.9738
1
6.941
Li
3
22.9898
Na
11
39.0983
K
4
3
12
5
6
21
22
23
87.62
88.9059
91.224
92.9064
95.94
Rb
Sr
Y
Zr
Nb
37
132.905
38
137.327
40
178.49
41
180.948
19
85.4678
Cs
55
(223)
Fr
87
20
4
Ba
39
La-Lu
56
226.025
Ra
88
Ac-Lr
24
7
25
8
9
10
In
Sn
Sb
Te
I
Xe
47
196.967
48
200.59
49
204.383
50
207.19
51
208.980
52
(210)
53
(210)
54
(222)
Mo
Tc
Ru
Rh
Pd
42
183.85
43
186.207
44
190.2
45
192.22
46
195.08
Ir
Pt
77
(276)
78
(281)
Db
Cd
107.868
Os
105
Ag
106.42
76
(277)
Sg
106
Bh
107
Hs
108
Mt
109
Ds
110
127.60
35
126.905
Au
79
(280)
Rg
111
Hg
80
(285)
Cn
112
Br
18
112.411
102.906
Re
34
Cl
As
101.07
75
(270)
17
79.904
33
121.757
(98)
W
16
Ge
30
74
(271)
P
15
74.9216
32
118.710
29
Ta
Si
14
72.61
10
Ga
28
73
(268)
Al
13
69.723
9
35.4527
31
114.82
27
Hf
Rf
12
26
72
(265)
104
11
F
8
2
Tl
Pb
Bi
Po
At
81
(284)
82
(289)
83
(288)
84
(293)
85
(294)
Uut
113
Fl
114
Uup
115
Lv
116
Uus
117
36
131.29
Rn
86
(294)
Uuo
118
NAME:____________________________
Student Number:______________________
2.
Fill in each blank with the word or short phrase that best completes the sentence.[13 marks]
(a)
The colour observed when a lithium salt is heated in a Bunsen burner flame is ________.
(b)
A boron atom is ___________________ electronegative than an oxygen atom.
(c)
The alkali metal in the 3rd period is _______________________________.
Write the name (not the symbol).
(d)
The only element in Group 1 that is not a metal is _________________________.
Write the name (not the symbol).
(e)
Ionization energy is defined as the energy required for an electron to be ______________
__________ a neutral atom in the gas phase.
(f)
The alkaline earth metal whose oxide reacts with both acid and base is ______________.
Write the name (not the symbol).
(g)
The gas released when CaCO3 is heated is ________. Write the formula (not the name).
(h)
One typical property of a metal is ______________________________________.
(i)
In the first step of purification of bauxite, ___________________ is added to the ore.
Contaminants like iron oxides can then be removed by ________________________.
(j)
Hard water contains ions such as ___________. Write a formula (not a name).
(k)
The sign of a bond dissociation enthalpy (∆BDH) is always ____________________.
(l)
The element of Group 14 with the smallest atomic radius is ____________________.
Write the name (not the symbol).
3.
Write balanced chemical equations for each of the following reactions.
Include states of matter. If no reaction occurs, write “NO REACTION”.
[8 marks]
(a)
Rubidium (Rb) is added to bromine (Br2(l)) and the reaction warmed to initiate reaction.
(b)
Lithium is burned in an atmosphere of oxygen.
(c)
Aluminium is added to strong aqueous acid.
(d)
Barium carbonate (BaCO3) is added to strong aqueous acid.
NAME:____________________________
4.
Student Number:______________________
Complete the following table.
[4 marks]
Chemical Formula
Name
Li3N
beryllium chloride
CoBr2
iron(III) oxide
5.
Complete the table below. Provide the best Lewis diagram for each compound, or one
representative of the best set of Lewis diagrams for molecules with resonance structures.
Include any non-zero formal charges on the appropriate atom(s).
[15 marks]
The central atom of each molecule/ion has been underlined.
Chemical
Formula
IBr4−
NO+
2
SO3
Lewis Diagram
Electron
Group
Geometry
(name)
Molecular
Geometry
(name)
Drawing of Molecule
with Bond Angles
Labeled
NAME:____________________________
6.
Student Number:______________________
The following graph shows the enthalpies of electronic attraction in period 2: [4 marks]
Answer the following questions using concepts from atomic theory
(a)
Explain the overall trend to increasingly negative enthalpies of electronic attraction from
left to right across the period.
[2 marks]
(b)
Explain why beryllium has no measurable enthalpy of electronic attraction.
[2 marks]
NAME:____________________________
Student Number:______________________
7.
Place the following ions in order of size, from smallest to largest: N3-, O2-, F-.
Explain briefly why the order you gave is the correct one.
[3 marks]
8.
The electrolysis of aqueous sodium chloride solution, the chlor-alkali process, is the main
industrial source of chlorine gas.
[6 marks]
Write a balanced reaction for this process. Include all states of matter.
[2 marks]
(a)
(b)
Worldwide production of chlorine by the chlor-alkali process is approximately 44 million
tonnes per year. What mass of sodium chloride is used on an annual basis in this process?
Express your answer in million tonnes.
[4 marks]
1 tonne = 1000 kg
NAME:____________________________
Student Number:______________________
9.
Nitrous oxide consists of an oxygen atom and two nitrogen atoms. It is a neutral molecule.
[4 marks]
Include any non-zero formal charges on the appropriate atom(s).
Not all central atom choices will lead to reasonable Lewis diagrams – but at least one will!
(a)
Draw the best Lewis diagram you can if the central atom is oxygen.
(b)
Draw the best Lewis diagram you can if the central atom is nitrogen.
(c)
Based on your answers to parts (a) and (b), which atom is most likely to be the central atom
in nitrous oxide? Briefly explain your choice.
Credit will only be given for this part of the question if there is a reasonable Lewis diagram
presented for the chosen central atom.
NAME:____________________________
Student Number:______________________
Some Useful Constants and Formulae
Fundamental Constants and Conversion Factors
Atomic mass unit (u) 1.660 539 × 10-27 kg
Avogadro's number
6.022 141 × 1023 mol–1
Bohr radius (a0)
5.291 772 × 10-11 m
Electron charge (e)
1.602 177 × 10-19 C
Electron mass
5.485 799 × 10-4 u
Ideal gas constant (R) 8.314 462 J·mol-1·K-1
8.314 462 m3·Pa·mol-1·K-1
Planck's constant
Proton mass
Neutron mass
Rydberg Constant (RH)
Speed of light in vacuum
Standard atmospheric pressure
Formulae
Band of Stability Graph
The graph at the right shows the band of stability.
Stable isotopes are in black. Isotopes that exist but
are not stable are shown in varying shades of gray
with the shades of gray corresponding to different
half-lives.
The original version of the graph used a rainbow colour scale.
http://commons.wikimedia.org/wiki/File:Isotopes_and_half-life_eo.svg
6.626 070 × 10-34 J·Hz-1
1.007 277 u
1.008 665 u
2.179 872 x 10-18 J
2.997 925 x 108 m·s-1
1 bar = 100 kPa
NAME:____________________________
1
Student Number:______________________
CHEM 1000 Standard Periodic Table
18
1.0079
H
1
6.941
2
13
14
15
16
17
9.0122
10.811
12.011
14.0067
15.9994
18.9984
Li
3
22.9898
Na
11
39.0983
K
19
85.4678
Be
4
7
8
9
10
25
26
27
28
29
30
87.62
88.9059
91.224
92.9064
95.94
(98)
101.07
102.906
106.42
107.868
112.411
Ba
Y
La-Lu
56
226.025
Ra
Ac-Lr
88
Zr
Nb
Mo
Tc
40
178.49
41
180.948
42
183.85
43
186.207
Ge
As
32
118.710
33
121.757
Rh
Pd
Ag
Cd
In
Sn
Sb
46
195.08
47
196.967
48
200.59
49
204.383
50
207.19
51
208.980
Ta
W
Re
Os
Ir
Pt
74
(271)
75
(270)
76
(277)
77
(276)
78
(281)
Bh
Ga
31
114.82
45
192.22
73
(268)
Sg
P
15
74.9216
Ru
Hf
Db
Si
14
72.61
44
190.2
72
(265)
Rf
N
7
30.9738
13
69.723
24
39
C
6
28.0855
Al
11
23
Sr
Fr
6
22
38
137.327
87
5
21
Rb
Cs
4
20
37
132.905
55
(223)
3
12
B
5
26.9815
Hs
Mt
Ds
Au
79
(280)
Rg
Hg
80
(285)
Cn
O
F
8
9
35.4527
16
17
79.904
34
35
126.905
127.60
Cl
Br
I
Xe
54
(222)
Pb
Bi
Po
At
83
(288)
84
(293)
85
(294)
Lv
Uus
104
105
106
107
108
109
110
111
112
113
114
115
116
117
138.906
140.115
140.908
144.24
(145)
150.36
151.965
157.25
158.925
162.50
164.930
167.26
168.934
173.04
174.967
La
Ce
Pr
Nd
Pm
Sm
Eu
Gd
Tb
Dy
Ho
Er
Tm
Yb
57
227.028
58
232.038
59
231.036
60
238.029
61
237.048
65
(247)
66
(251)
Ac
89
Th
90
Pa
91
U
92
Np
93
62
(240)
Pu
94
63
(243)
Am
95
64
(247)
Cm
96
Bk
97
Cf
98
67
(252)
Es
99
68
(257)
Fm
100
69
(258)
Md
101
36
131.29
53
(210)
82
(289)
Uup
18
Te
Tl
Fl
10
52
(210)
81
(284)
Uut
2
70
(259)
No
102
Rn
86
(294)
Uuo
118
Lu
71
(262)
Lr
103
Developed by Prof. R. T. Boeré (updated 2014)