Version A Team Copy

Chemistry 100: Midterm Exam Practice

·  Expect the exam to be a cross between:

o  questions like these (taken from Fall 2002 & Winter 2003 Exams),

o  questions on the Team Exercises, and

o  homework problems.

Team Name: ______
Leader: ______
Recorder: ______
Spokesperson: ______/ Worker: ______
Worker: ______
Worker: ______
1
H
1.008
2.1 / 1
H
1.008
2.1 / Atomic Number
Symbol
Atomic Mass
Pauling’s Electronegativity / 2
He
4.003
3
Li
6.941
1.0 / 4
Be
9.012
1.5 / 5
B
10.81
2.0 / 6
C
12.01
2.5 / 7
N
14.01
3.0 / 8
O
16.00
3.5 / 9
F
19.00
4.0 / 10
Ne
20.18
11
Na
22.99
0.9 / 12
Mg
24.31
1.2 / 13
Al
26.98
1.5 / 14
Si
28.09
1.8 / 15
P
30.97
2.1 / 16
S
32.07
2.5 / 17
Cl
35.45
3.0 / 18
Ar
39.95
19
K
39.10
0.8 / 20
Ca
40.08
1.0 / 21
Sc
44.96 / 22
Ti
47.88 / 23
V
50.94 / 24
Cr
52.00 / 25
Mn
54.94 / 26
Fe
55.85 / 27
Co
58.93 / 28
Ni
58.69 / 29
Cu
63.55 / 30
Zn
65.39 / 31
Ga
69.72
1.8 / 32
Ge
72.61
1.8 / 33
As
74.92
2.0 / 34
Se
78.96
2.4 / 35
Br
79.90
2.8 / 36
Kr
83.80
37
Rb
85.47
0.8 / 38
Sr
87.62
0.9 / 39
Y
88.91 / 40
Zr
91.22 / 41
Nb
92.91 / 42
Mo
95.94 / 43
Tc
(99) / 44
Ru
101.1 / 45
Rh
102.9 / 46
Pd
106.4 / 47
Ag
107.9 / 48
Cd
112.4 / 49
In
114.8
1.7 / 50
Sn
118.7
1.8 / 51
Sb
121.8
1.9 / 52
Te
127.6
2.1 / 53
I
126.9
2.5 / 54
Xe
131.3
55
Cs
132.9
0.7 / 56
Ba
137.3
0.9 / 57
*La
138.9 / 72
Hf
178.5 / 73
Ta
180.9 / 74
W
183.9 / 75
Re
186.2 / 76
Os
190.2 / 77
Ir
192.2 / 78
Pt
195.1 / 79
Au
197.0 / 80
Hg
200.6 / 81
Tl
204.4
1.8 / 82
Pb
207.2
1.9 / 83
Bi
209.0
1.9 / 84
Po
(209)
2.0 / 85
At
(210)
2.2 / 86
Rn
(222)
87
Fr
(223) / 88
Ra
226.0 / 89
†Ac
227.0 / 104
Rf
(261) / 105
Db
(262) / 106
Sg
(263) / 107
Bh
(262) / 108
Hs
(265) / 109
Mt
(268)
*Lanthanide
Series / 58
Ce
140.1 / 59
Pr
140.9 / 60
Nd
144.2 / 61
Pm
(145) / 62
Sm
150.4 / 63
Eu
152.0 / 64
Gd
157.3 / 65
Tb
158.9 / 66
Dy
162.5 / 67
Ho
164.9 / 68
Er
167.3 / 69
Tm
168.9 / 70
Yb
173.0 / 71
Lu
175.0
†Actinide
Series / 90
Th
232.0 / 91
Pa
231.0 / 92
U
238.0 / 93
Np
237.0 / 94
Pu
(244) / 95
Am
(243) / 96
Cm
(247) / 97
Bk
(247) / 98
Cf
(251) / 99
Es
(252) / 100
Fm
(257) / 101
Md
(258) / 102
No
(259) / 103
Lr
(260)
1s
2s 2p
3s 3p 3d
4s 4p 4d 4f
5s 5p 5d 5f / HONClBrIF
  1. (10 pts) Without referring to any periodic table (including the one on the front page of this exam, write the first 3 rows of the periodic table including element symbol and atomic number. You must sign and date the statement to get credit for this problem.

I certify that I did not look at any reference while solving this problem.

Signed: ______Date: ______

1
H / 2
He
3
Li / 4
Be / 5
B / 6
C / 7
N / 8
O / 9
F / 10
Ne
11
Na / 12
Mg / 13
Al / 14
Si / 15
P / 16
S / 17
Cl / 18
Ar
  1. (2 pts) Which of the following changes is/are endothermic for the underlined object?
    i. baking a potato iv. a lit light bulb shining
    ii. a person being burned by a pan v. a person digesting food
    iii. a wood log burning
    A. iii only D. i and iv
    B. iii and iv E. i and ii
    C. iii and iv
  2. (2 pts) Which of the following are elements?
    i. KOH iv. carbon tetrachloride
    ii. Ne v. calcium
    iii. CO
    A. i, ii, and iii D. ii and v
    B. iv and v E. ii, iii, and v
    C. ii and iii
  3. (2 pts) Which of the following is not a particulate sample of matter?
    A. An oxygen molecule D. A nickel atom
    B. A human egg cell E. A hemoglobin molecule
    C. An electron
  4. 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.
    Heat
    I2 (s) + Heat à I2 (g) or I2 (s) ------> I2 (g)
    b. (5 pts) Later, an ice cube was held next to the top edge of the flask. What happened?
    Crystals formed on the edge of the glass.
    c. (5 pts) Write the equation for the process from (b).
    I2 (g) - Heat à I2 (s) or
    I2 (g) à I2 (s) + Heat
    d. (5 pts) Which of the processes was endothermic for the Iodine? Briefly describe why.
    I2 (s) + Heat à I2 (g) heat went into the iodine
  5. (2 pts) Which of the following properties is/are classified as physical?
    i. the odor of glass cleaning solution
    ii. the color of chlorine gas
    iii. the electrical conductivity of copper wire
    iv. the ability of milk to sour
    v. a compound does not react with bromine
    A. i only D. i, ii, and iii
    B. ii only E. iv and v
    C. i and ii
  6. (2 pts) Which of the following properties is/are classified as chemical?
    i. the taste of honey
    ii. the ability of hair to stretch
    iii. the corrosive character of hydrochloric acid
    iv. the combustibility of ethanol
    v. the softness of talc
    A. i and ii D. iv only
    B. i, ii, and v E. iii and iv
    C. iii only
  7. (2 pts) Which of the following substances is/are homogeneous?
    i. mineral oil iv. sugar
    ii. a plant leaf v. freshly squeezed lemonade
    iii. sausage
    A. i only D. i and iv
    B. ii only E. i, ii, and iv
    C. iv only
  8. (2 pts) In which of the following pairs of substances will there be a net attractive electrostatic force?
    A. Two positively charged table tennis balls
    B. A negatively charged piece of dust and a positively charged piece of dust
    C. A positively charged sodium ion and a positively charged potassium ion
    D. A negatively charged chloride ion and a negatively charged bromide ion
    E. Two negatively charged pith balls
  1. (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. The existence of isotopes
    B. Mass is conserved in a chemical change
    C. Nearly all of the mass of an atom is concentrated in the nucleus
    D. The total charge of the electrons of an atom exactly balances the positive
    charge of the nucleus
    E. The planetary model of the atom has been shown to be incorrect
  2. (2 pts) Which of the three major subatomic particles has/have a charge of +1?
    Proton
  3. (2 pts) The nuclear symbol of an isotope of potassium is . Indicate the number of protons, number of neutrons, atomic number, and mass number of the isotope.

Number of protons / Number of neutrons / Atomic number / Mass number
A. / 19 / 22 / 19 / 41
B. / 22 / 19 / 41 / 19
C. / 19 / 41 / 19 / 22
D. / 41 / 19 / 22 / 19
E. / 41 / 19 / 41 / 22
  1. (2 pts) Which of the three major subatomic particles has/have a mass of approximately one amu?
    proton, neutron
  2. (3 pts) Isotopes of an element vary in mass because of differing numbers of:
    neutrons
  3. (5 pts) Write the elemental formula for the following elements:

Element / Elemental Formula
i. / nitrogen / N2
ii. / sulfur / S
iii. / lithium / Li
iv. / bromine / Br2
v. / oxygen / O2
  1. (3 pts). The alkali metal kalium was discovered in 1807. What is its English name and symbol?
    Potassium
  2. (10 pts) Neatly sketch and label the apparatus/experiment that disproved the Plum Pudding model of the atom.

Rutherford experiment

  1. 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?
    columns
    b. (3 pts) Write the names of three of these groups.
    alkali metals, alkaline earths, transition metals, halogens, noble gases
    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:
    Calcium: 1s22s22p63s23p64s2 (easiest one!)
    Cobalt: 1s22s22p63s23p64s23d7
    Chlorine: 1s22s22p63s23p5
    e. (3 pts) Write the name of the group that the element belongs to:
    Calcium: alkaline earths
    Cobalt: transition metals
    Chlorine: halogens
    f. (2 pts) How many electrons are your element’s valence (outer shell)?
    Calcium: 2
    Cobalt: 2
    Chlorine: 7
  2. 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.
    1s22s22p63s23p64s24d104p5
    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.
    d. (2 pts). Bromine has two stable isotope with masses 79 and 81. Write the nuclear symbol for these isotopes.
    79 81
    Br Br
    35 35
  3. (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: / Black Sharpie / Black Marker (Permanent) / Blue Overhead Pen
Fluid: / Water / Rubbing Alcohol / Water
Resulting Paper:
Sample Type: (homogenous/ heterogeneous/ undetermined) / homogenous/ or undetermined / heterogeneous / heterogeneous