CHEM 108– Test #2A (1985)
Dr. Bolaños
Fall 2009
Name:____________________________________________ Student #:______________________________
PLEASE TEAR OFF THE SCRATCH SHEET and PERIODIC TABLE AT THE END OF THIS EXAM and sign the Honor Code
below. There are 26 questions on this examination totaling 105 points (exam is out of 100 pts; point values are clearly stated on
problems). You have 1.5 hours to complete this examination and may only use a basic scientific calculator and provided
Periodic Table. All work must be shown for credit (no work needed for multiple choice or fill-in questions). Clearly write your
name of the scratch sheet of paper and submit at the end of the examination period. If you need additional scratch paper or
further clarification, please raise your hand. Good Luck! **I certify the work below is my own. I did not give nor receive
any assistance and I followed all rules set-forth.
Signature:
______________________________________________________________
PART A – Multiple Choice:
Please record the answers to Questions 1-20 on your scantron. (1.5 pts each; 30 pts total)
1. When a metal and a nonmetal react, the __________ tends to lose electrons and the __________ tends to
gain electrons.
A) metal, metal
B) nonmetal, nonmetal
C) metal, nonmetal
D) nonmetal, metal
E) None of the above, these elements share electrons.
2. Potassium is a __________ and arsenic is a __________.
A) metal, nonmetal
B) metal, metal
C) metal, metalloid
D) metalloid, nonmetal
E) nonmetal, metal
3. Elements in Group 2A are known as the __________.
A) alkaline earth metals
B) alkali metals
C) chalcogens
D) halogens
E) noble gases
4. The element __________ is the most similar to strontium in chemical and physical properties.
A) Li
B) At
C) Rb
D) Ba
E) Cs
5. Which one of the following does not occur as diatomic molecules in elemental form?
A) oxygen
B) nitrogen
C) sulfur
D) hydrogen
E) bromine
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CHEM 108– Test #2A (1985)
Dr. Bolaños
Fall 2009
6. Which pair of atoms constitutes a pair of isotopes of the same element?
A) 146 X 147 X
B)
14
6
C)
17
9
D)
19
10
E)
20
10
X
12
6
X
X
17
8
X
X
19
9
X
X
21
11
X
7. The atomic number indicates __________.
A) the number of neutrons in a nucleus
B) the total number of neutrons and protons in a nucleus
C) the number of protons or electrons in a neutral atom
D) the number of atoms in 1 g of an element
E) the number of different isotopes of an element
8. Which atom has the largest number of neutrons?
A) phosphorus-30
B) chlorine-37
C) potassium-39
D) argon-40
E) calcium-40
9. Oxygen forms an ion with a charge of __________.
A) 2B) 2+
C) 3-
D) 3+
E) 6+
10. From the following list of substances and specific heats, choose the one that will have the lowest temperature
after absorbing 100.0 kJ of heat. Assume identical masses of each substance start at the same initial
temperature.
a) Lead , 0.128 J/g * oC
b) Copper, 0.385 J/g * oC
c) Ethanol, 2.42 J/g * oC
d) Water, 4.184 J/g * oC
e) Not enough information
11. What is the formula of the compound formed between strontium ions and nitrogen ions?
A) SrN
B) Sr3 N 2
C) Sr2 N 3
D) SrN 2
E) SrN 3
12. The formula of a salt is XCl2 . The X-ion in this salt has 28 electrons. The metal X is __________.
A) Ni
B) Zn
C) Fe
D) V
E) Pd
13. How many kilojoules are there in a 255 Calorie snack bar?
a. 2.55 × 105
b. 1.07 × 103
14. The temperature of 25 °C is __________ in Kelvins.
A) 103
B) 138
C) 166
D) 248
2
c. 60.9 d. 1 × 103
E) 298
e. none of these
Dr. Bolaños
CHEM 108– Test #2A (1985)
Fall 2009
15. If matter is uniform throughout and cannot be separated into other substances by physical processes, but can
be decomposed into other substances by chemical processes, it is called a (an) __________.
A) heterogeneous mixture
B) element
C) homogeneous mixture
D) compound
E) mixture of elements
16. Which one of the following is the highest temperature?
A) The boiling point of water
B) 220 °F
C) 373 K
D) 100 °C
E) All of the above are identical temperatures
17. The law of constant composition applies to __________.
A) solutions
B) heterogeneous mixtures
C) compounds
D) homogeneous mixtures
E) solids
18. Which of the following are chemical processes?
1. rusting of a nail
2. freezing of water
3. decomposition of water into hydrogen and oxygen gases
4. compression of oxygen gas
A) 2, 3, 4
B) 1, 3, 4
C) 1, 3
D) 1, 2
E) 1, 4
19. Gases and liquids share the property of __________.
A) compressibility
B) definite volume
C) incompressibility
D) indefinite shape
E) definite shape
20. An element in the upper right corner of the periodic table __________.
A) is either a metal or metalloid
B) is definitely a metal
C) is either a metalloid or a non-metal
D) is definitely a non-metal
E) is definitely a metalloid
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CHEM 108– Test #2A (1985)
Dr. Bolaños
Fall 2009
PART B – Short Answer/Computation
21. Please fill-in the correct response for each of the following. (3 pts each, 18 pts total)
Compound Formula
Compound Name
FeBr2
tetraphosphorus pentoxide
Tin (IV) hydroxide
aluminum acetate
ICl2
Vanadium (IV) sulfate
22. Please fill-in the correct response for each of the following. (1.5 pt each blank, 12 pts total)
a. Indium has __________ valence electrons; the halogen on period 5 is _________________________.
b. When a gasesous vapor is converted to the liquid state, energy is absorbed or released (circle one)?
c. A small amount of salt dissolved in water is a(n) element, compound, or mixture (circle one).
d. Is brass heterogeneous or homogeneous (circle one)?
e. True or False (circle one): Noble gases are poor conductors of heat and electricity.
f.
The specific heat of water is higher or lower (circle one), relative to most liquids.
g. When Fe-57 undergoes reaction, three electrons are “transferred”. The charge of the iron ion is _______,
23. Please fill in the table below with the correct information. (15 pts total, 1.5 pts each)
Symbol of
Element/Ion:
A
X
# protons
82
131
I
# neutrons
# electrons
Mass number
32
25
57
127
80
-
4
Element/Ion
Charge
Dr. Bolaños
CHEM 108– Test #2A (1985)
Fall 2009
24. Rubidium has two known isotopes with masses 84.9117 amu and 86.9092 amu. If the weighted average
atomic mass is 85.4678 amu, what are the relative percentages of each isotope? Hint: Solve this problem
relative to only one variable. (9 pts.)
25. Calculate the mass in grams for a sample of titanium that loses 15.2 kJ when it cools from 365 oF to 107.6 oF.
The specific heat of titanium is 0.523 J/g * oC. Hint: Be observant, please! (10 pts)
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Dr. Bolaños
CHEM 108– Test #2A (1985)
Fall 2009
26. A 48.9 gram piece of chocolate cake contains 55% fat, 36% protein, and 9% carbohydrates. One cup of 4%
milk contains 12 g carbohydrates, 9 grams of proteins and 9 grams of fat. A 154-lb adult wakes up for a
midnight snack and eats this entire piece of cake and drinks 1 cup of 4% milk, before returning to bed. If the
154-lb adult burns off 2.7 x 105 J of energy for every hour they sleep, how many hours of sleep are needed to
“burn off” this midnight snack? Please show all work for credit. (12 pts)
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