Download Chemistry 139

Exam 1 – Version A
Course:
Instructor:
Chemistry 100
Armando Herbelin x2882
[email protected]
Calculator is OK, No notes.
50 min.
Proctoring:
Time Limit:
Winter 2003
Name: _______________________
Be sure to select Letter (A/B/C/D/E) options on multiple choice questions.
1
1
H
H
1.008
1.008
2.1
3
2
Atomic Number
Symbol
Atomic Mass
Pauling’s Electronegativity
2.1
He
4.003
4
5
6
7
8
9
10
Li
Be
B
C
N
O
F
Ne
6.941
9.012
10.81
12.01
14.01
15.99
19.00
20.18
1.0
11
1.5
12
2.0
13
Al
2.5
14
Si
3.0
15
P
3.5
16
S
4.0
17
Cl
26.98
28.09
30.97
32.07
35.45
1.5
1.8
2.1
2.5
3.0
Na Mg
22.99
24.31
0.9
19
1.2
20
K
Ca
39.10
40.08
0.8
37
1.0
38
Rb
Sr
85.47
87.62
0.8
55
0.9
56
Cs
Ba
132.9
137.3
0.7
87
0.9
88
Fr
Ra
(223)
226.0
*
Lanthanide
Series
†
Actinide
Series
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f
6s 6p 6d 6f
7s 7p 7d 7f
21
Sc
22
Ti
23
V
24
Cr
25
Mn
26
Fe
27
Co
28
Ni
29
Cu
30
Zn
31
Ga
32
Ge
33
As
34
Se
35
Br
44.96
47.88
50.94
52.00
54.94
55.85
58.93
58.69
63.55
65.39
69.72
72.61
74.92
78.96
79.90
1.8
1.8
2.0
2.4
2.8
39
Y
88.91
40
Zr
91.22
41
Nb
42
Mo
43
Tc
44
Ru
45
Rh
46
Pd
47
Ag
48
Cd
49
In
50
Sn
51
Sb
52
Te
53
I
92.91
95.94
(99)
101.1
102.9
106.4
107.9
112.4
114.8
118.7
121.8
127.6
126.9
1.7
1.8
1.9
2.1
2.5
81
Tl
82
Pb
83
Bi
84
Po
85
At
204.4
207.2
209.0
(209)
(210)
1.8
1.9
1.9
2.0
2.2
68
69
70
71
57
La
72
Hf
73
Ta
138.9
178.5
180.9
*
89
Ac
†
227.0
58
104
105
74
75
76
77
78
W
Re
Os
Ir
Pt
183.9
186.2
190.2
192.2
195.1
197.0
200.6
106
107
108
109
65
66
67
Rf
Db Sg
Bh Hs Mt
(261)
(262)
(263)
(262)
(265)
(268)
59
60
61
62
63
64
Ce
Pr
140.1
140.9
79
80
Au Hg
Nd Pm Sm Eu Gd Tb Dy Ho
144.2
90
91
92
Th
Pa
U
232.0
231.0
238.0
(145)
150.4
152.0
157.3
158.9
93
94
95
96
97
162.5
Er Tm Yb Lu
164.9
167.3
168.9
173.0
175.0
100
101
102
103
98
99
Np Pu Am Cm Bk
Cf
Es Fm Md No
Lr
237.0
(251)
(252)
(260)
(244)
HONClBrIF
(243)
(247)
(247)
(257)
(258)
(259)
18
Ar
39.95
36
Kr
83.80
54
Xe
131.3
86
Rn
(222)
1.
2.
3.
(2 pts) Which of the following changes is/are endothermic for the underlined object?
i. baking a potato
ii. a person being burned by a pan
iii. a wood log burning
iv. a lit light bulb shining
v. a person digesting food
A. iii only
B. iii and iv
C. iii and iv
D. i and iv
E. i and ii
(2 pts) Which of the following are elements?
i. KOH
ii. Ne
iii. CO
iv. carbon tetrachloride
v. calcium
A. i, ii, and iii
B. iv and v
C. ii and iii
D. ii and v
E. ii, iii, and v
(2 pts) Which of the following correctly matches each sample with its classification as either
macroscopic, microscopic, or particulate?
A.
B.
C.
D.
E.
4.
Macroscopic
protein molecule
protein molecule
crystal on polished metal
cat hair
cat hair
Microscopic
cat hair
crystal on polished metal
cat hair
crystal on polished metal
protein molecule
Particulate
crystal on polished metal
cat hair
protein molecule
protein molecule
crystal on polished metal
(2 pts) Which of the following is not a particulate sample of matter?
A.
B.
C.
An oxygen molecule
A human egg cell
An electron
D.
E.
A nickel atom
A hemoglobin molecule
____/8
5.
A chemistry instructor puts some Iodine crystals (I2 (s)) in a flask. Upon warming the flask, a
purple cloud appears.
a. (5 pts) Write the chemical equation that describes this process.
b. (5 pts) Later, an ice cube was held next to the top edge of the flask. What happened?
c. (5 pts) Write the equation for the process from (b).
d. (5 pts) Which of the processes was endothermic for the Iodine? Briefly describe why.
I did this demonstration with a different apparatus last quarter –
this time it was the U-shaped tube.
Ice
Purple
Cloud
I2
____/20
6.
7.
8.
9.
(2 pts) Which of the following properties is/are classified as physical?
i.
ii.
iii.
iv.
v.
the odor of glass cleaning solution
the color of chlorine gas
the electrical conductivity of copper wire
the ability of milk to sour
a compound does not react with bromine
A.
B.
C.
i only
ii only
i and ii
D.
E.
i, ii, and iii
iv and v
(2 pts) Which of the following properties is/are classified as chemical?
i.
ii.
iii.
iv.
v.
the taste of honey
the ability of hair to stretch
the corrosive character of hydrochloric acid
the combustibility of ethanol
the softness of talc
A.
B.
C.
i and ii
i, ii, and v
iii only
D.
E.
iv only
iii and iv
(2 pts) Which of the following substances is/are homogeneous?
i.
ii.
iii.
mineral oil
a plant leaf
sausage
iv.
v.
sugar
freshly squeezed lemonade
A.
B.
C.
i only
ii only
iv only
D.
E.
i and iv
i, ii, and iv
(2 pts) In which of the following pairs of substances will there be a net attractive electrostatic
force?
A.
B.
C.
D.
E.
Two positively charged table tennis balls
A negatively charged piece of dust and a positively charged piece of dust
A positively charged sodium ion and a positively charged potassium ion
A negatively charged chloride ion and a negatively charged bromide ion
Two negatively charged pith balls
____/8
10.
(2 pts) One of the main features of Dalton's atomic theory which is no longer considered valid
is: All atoms of each element are identical in every respect. Which of the following is the best
explanation of why this feature is no longer considered valid?
A.
B.
C.
D.
E.
The existence of isotopes
Mass is conserved in a chemical change
Nearly all of the mass of an atom is concentrated in the nucleus
The total charge of the electrons of an atom exactly balances the positive
charge of the nucleus
The planetary model of the atom has been shown to be incorrect
11.
(2 pts) Which of the three major subatomic particles has/have a charge of +1?
12.
41
K
(2 pts) The nuclear symbol of an isotope of potassium is 19 . Indicate the number of protons,
number of neutrons, atomic number, and mass number of the isotope.
A.
B.
C.
D.
E.
Number of protons
19
22
19
41
41
Number of neutrons
22
19
41
19
19
Atomic number
19
41
19
22
41
Mass number
41
19
22
19
22
13.
(2 pts) Which of the three major subatomic particles has/have a mass of approximately one
amu?
14.
(3 pts) Isotopes of an element vary in mass because of differing numbers of:
____/11
15.
(5 pts) Write the elemental formula for the following elements:
Element
i.
nitrogen
ii.
sulfur
iii.
lithium
iv.
bromine
v.
oxygen
Elemental Formula
16.
(3 pts). The alkali metal kalium was discovered in 1807. What is its English name and symbol?
17.
(10 pts) Neatly sketch and label the apparatus/experiment that disproved the Plum Pudding
model of the atom.
____/18
18.
The element bromine (name for the Greek word for stench, brômos) was discovered in 1826 by
Antoine J. Balard.
a. (3 pts). Write its electronic configuration.
On the figure below:
b. (3 pts). Label the s, p, and d orbitals.
c. (2 pts). Fill in electrons for Bromine in the energy level diagram.
E
d. (2 pts). Bromine has two stable isotope with masses 79 and 81. Write the nuclear symbol for
these isotopes.
____/10
19.
Early chemists classified the elements by their chemical properties and gave these groups of
elements special names.
a. (3 pts) What feature of the periodic table do these groups correspond to?
b. (3 pts) Write the names of three of these groups.
c. (0 pts) Choose one of the following elements and circle it.
(Read d – f before making your choice!)
Calcium
Cobalt
Chlorine
d. (3 pts) Write the electronic configuration of that element:
e. (3 pts) Write the name of the group that the element belongs to:
f. (2 pts) How many electrons are your element’s valence (outer shell)?
____/12
20.
(7 pts) Express the following numbers in scientific notation (use your calculator for
calculations).
Number
Scientific Notation
0.0821
1024.2
1000
50.2
a million
3.14159 × 0.0005
( 6.02 × 1023 ) ÷ ( 1,000,000,000 )
Problem #20 is part of Unit C – we won’t get to this section before the exam.
21.
(6 pts) A dedicated Chemistry 100 student tried to repeat the paper chromatography experiment
from lecture. Based on the individual results, Label each of the following samples as
homogenous, heterogeneous, or undetermined.
Sample:
Fluid:
Black Sharpie
Water
Black Marker
(Permanent)
Rubbing Alcohol
Blue Overhead
Pen
Water
Resulting Paper:
Sample Type: (homogenous/
heterogeneous/ undetermined)
____/13