EK 1001 GChem

Table of Contents
Questions

P:

1. Atoms, Molecules, and Quantum Mechanics ...... 1 - 157 ............ 1
Significant Figures ......................................................... 1 - 2 ......................
Atoms ........................................................................ 3- 34 ....................
Periodic Table .............................................................. 35- 72 ..................
Molecules .................................................................... 73 -107 .................
Chemical Reactions and Chemical Equilibrium ....................... 108- 129 ................
Bonding in Solids .......................................................... 130 -136 ...............
Quantum Numbers ......................................................... 137 -141 ...............
Heisenberg Uncertainty Principle ....................................... 142- 143 ...............
Energy Level of Electrons ................................................ 144 -157 ...............

1
1
3
6
9
11
1~
1~
1~

2. Gases, Kinetics, and Chemical Equilibrium ........ 158- 295 ......... 1'
Gases ........................................................................ 158-208 ...............
Real Gases ................................................................... 209- 227 ...............
Kinetics ...................................................................... 228 -_273 ...............
Equilibrium ................................................................. 274-295 ...............

14
2C
22
28

3. Thermodynamics .......................................... 296- 438 ... ...... 3:
Systems ...................................................................... 296- 304 ...............
Heat .... ; ..................................................................... 305 - 328 ...............
Work ......................................................................... 329 -348 ...............
Thermodynamic Functions ............................................... 349- 351. ..............
Internal Energy ............................................................. 352-355 ...............
Temperature ................................................................ 356- 366 ...............
Enthalpy ...................................................................... 367- 390 ...............
Entropy ...................................................................... 391- 410 ...............
Gibbs Free Energy ......................................................... 411- 438 ...............

32
32
35
37
37
38
39
42
44


Questions

Page

. Solutions ................................................... 439- 568 ..... .... 48
Solutions ..................................................................... 439- 449 ............... 48
Colloids ...................................................................... 450 - 453 ............... 49
Electrolytes. . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 454 - 468 ............... 49
Solubility Guidelines ..................................................... 469-472 ............... 51
Units of Concentration... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 473 - 492 ............... 51
Solution Formation ........................................................ 493 - 504 ............... 53
Vapor Pressure ............................................................. 505- 528 ............... 54
Solubility.................................................................... 529- 558 ............... 57
Solubility Factors......................................................... 559- 568 ............... 60

. Heat Capacity, Phase Change, and Colligative
Properties .................................................. 569 - 715 ..... .... 62
Phases ........................................................................
Heat Capacity...............................................................
Calorimeters. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Phase Change ...............................................................
Phase Diagrams ............. : ...............................................
Colligative Properties ......................................................

569 - 578 ............... 62
579- 603 ............... 63
604 - 619 ............... 66
620- 651 ............... 67
652 - 689 ............... 70
690 -715 ............... 75

. Acids and Bases .......................................... 716- 860 ..... .... 79

Definitions .................................................................. 716 -755 ............... 79
Factors Determining Acid Strength ..................................... 756- 761 ............... 82
Hydrides ..................................................................... 762- 769 ............... 82
Equilibrium Constants for Acid-Base Reactions ....................... 770 782 ............... 83
Finding pH .................................................................. 783 -798 ............... 84
Salts .......................................................................... 799- 811 ............... 86
Titrations .................................................................... 812- 830 ............... 87
More Titrations and Buffered Solutions ................................ 831 - 841 ............... 89
Indicator and the End Point.. ............................................. 842- 844 ............... 90
Polyprotic Titrations ....................................................... 845 -860 ................ 90

'. Electrochemistry ......................................... 861 - 1001 .... .... 93
Oxidation-Reduction ....................................................... 861- 901 ............... 93
Oxidation-Reduction Titrations .......................................... 902- 918 ............... 96
Potentials ..................................................................... 919- 934 ............... 98
Balancing Redox Reactions .............................................. 935- 947 ............... 100
Galvanic Cell ................................................................ 948- 958 ............... 101
Free Energy and Chemical Energy ....................................... 959- 975 ............... 103
More Cells .................................................................. 976 -1001 .............. 105

llanations................................................... .. . .................... 109


IfE represents any real element, which of the fol
statements must be true concerning the elemet
shown above?

Significant Figures
'

How many significant figures are in 0.008010?

l.\

A. The value of A is larger than Z.
B. The value of Z is larger than A.
6. IfE is an ion, the value of Z is negative.
It The value of Z cannot be larger than the vah

A. 2
B. 3

c. 4
D. 6

If C for a sample of element E is zero, then:

\

The following values of a sample of gas were measured
in the lab: P = 1.5 atm; V = 10.3 L; and T = 298.0 K.
Based on these measurements, a student calculated the
number of moles using the equation PV = nRT. Which
calculated value has the correct number of significant
figures? (Note: the value of R is 0.08206 L atm K-1

A. A and Z are equal.
B. There are the same number of protons and n
in the sample.
C. There are the same number of protm

electrons in the sample.
D. The sample is ionized.

mor1)
A.
B.
C.
D.

The atomic number on the element E is represen1

0.63 mol
0.632 mol
0.6318 mol
0.63180 mol

A. A
B. Z

c.

c

D. A+Z

1.'Ct The mass number on the element E is representee

Atoms

A. A

B. Z

Refer to the hypothetical element E shown below to answer
questions 3-18.

c.

c

D. A+Z

1'4_ Which of the following is always true
relationship between A and Z on any stable elemc

~

Z on element E represents:
A.
B.
C.
D.

A.
B.
C.
D.

the number of neutrons.
the number of protons.
the number of neutrons plus protons.

the number of electrons.
~

~

~

A on element E represents:

Which of the following could not be true for an:
elementE?

A.
B.
C.
D.

A.
B.
C.
D.

the number of neutrons.
the number of protons.
the number of neutrons plus protons.
the number of electrons.

the number of electrons.
the number of protons.
the number of protons minus electrons.

the number of neutrons plus protons.

A.
B.
C.
D.

A good approximation of the mass of one atom of
element E in atomic mass units would be: K
A.
B.
C.
D.

There is more than one possible value for A.
There is more than one possible value for C.
There is more than one possible value for Z.
There is more than one possible value for A ·

':1:'3. If two different atoms of element E have d
values for A, they must be:

C on element E represents:

A.
B.
C.
D.
~

Z is greater than A.
A is great~r than Z.
Z is exactly half as great as A.
A minus Z gives the number of neutrons.

A
Z
A+Z
A+Z+C
1

different elements.
ions of the same element.
isotopes of the same element.
isomers of the same element.


)1

Questions in MLAT t;nennstry

If A of element E has a value of 22, then:

"ct...

A. Z must have a value of 11.
B. any form of element E must contain 22 electrons.
C. element E has an atomic weight of approximately
11 amu.
D. element E has an atomic weight of approximately

22 amu.

I. Protons
II. Neutrons
ID. Electrons
A. I only
B. llonly
C. I and III only
--D. I, II, and III

If A of element E has a value of 22, then one mole of
elementE:

'A._ has a mass of approximately 11 amu.
has a mass of approximately 22 amu.
C. weighs approximately 22 grams.
D. weighs approximately 22 x 6.02 x 1023 grams.

~

22-..

) If A of element E has a value of 12, ~
sample of element E represents approximately:

':A.
B.
B.D.

Y:l of an atom.

2 atoms.
Y:l mole of atoms.
2 moles of atoms.

Two different isotopes of an element are isolated as
neutral atoms. The atoms must have the same number
of:

Silicon exists as three different isotopes in nature.
These are Si28 , Si29 , and seo with the atomic weights of
27.98 amu, 28.98 amu, and 29.97 amu respectively.
Which isotope is likely to be most abundant in nature?
A. se8
B. Si29
C. Si30
D. They are nearly equal in abundance.

23.. Arsenic (As) exists as a single isotope in nature. Wha1
is the expected number of neutrons in this isotope?

If one mole of a sample of element E wei~ 4 grams,
A of element E has a value of approximately:

A.
B.
C.
D.

7
14

7 X 6.02 X 1023
14 X 6.02 X 1023

I
'24-~

A. 33
B. 38
c. 42
D. 45
How much does a 3-mole sample ofNa weigh?
A.
B.
C.
D.

'- The identity of element E can be attained with absolute
certainty by knowing . the value of which of the
following?

23 amu
69 amu
23 grams
69 grams

A. Z
B. A

c. c

~

D. A+Z

A. 2

B. 4

1.___ Which of the following has a mass of approximately 1

C. 2 X 6.02 X 1023
D. 4 X 6.02 X 1023

amu?
A.
B.
C.
D.

one proton
one electron
one atom of 12C
one mole of 12C

(}.__ Which of the following would have the greatest mass?
A.
B.
C.
D.

25 protons, 25 neutrons, and 23 electrons
24 protons, 25 neutrons, and 27 electrons
25 protons, 24 neutrons, and 27 electrons
B and C would both have exactly the same mass,
while A would be less

How many atoms of Mg are in a 48 g sample of soli
Mg?

@

The charge on one mole of electrons is given l:
Faraday's constant (F = 96,500 C/mol). What is tl
total charge of all the electrons in 2 grams of He?
A. 48,250 C
B. 96,500 c
c. 193,000 c
D. 386,000 C


27.

Which of the following represents the charge on one
mole of electrons?

34.

A. 1 e
B. 6.02x10 23 e
c. 1 e

D. 6.02x10 23 e
28.

The Periodic Table

A. 0
B. 1

Na and K belong to which family of elements?

2

A. the alkaline earth metals
B. the alkali metals
C. the transition metals
D. the representative elements.

D. 4
29.

Which of these elements, in its most common isotope,
has more protons than neutrons in its nucleus?

A. H
B. He

The members of the noble gas family are son
called the:

c.

)\ royal elements
B. inert gases
~ representative elements
D. halogens

e

D. U
30.

Which element, in its most common isotope, has more
neutrons than protons in its nucleus?

A. H
B. He

Alkaline earth metals generally form ions with a
of:

c.

A. +1
B. +2
c. -1
D. -2

e

D{ U

31.

Which of the following is a complete list of the isotopes
of carbon that are found in nature?

I4e
B. Be, I4e
C. 12e, Be, I4e
D. e, Ize, Be, I4e

38.
'

Lithium occurs naturally in only two isotopic forms,
lithium-6 and lithium-7. What can be said about the
relative abundances of the two isotopes?

.,

A.

32.

A. lose one electron.
B. lose two electrons.
C. gain one electron.
D. gain two electrons.

A. representative elements.
B. transduction metals.

C. transition metals.
D. alkaline earth metals.
'4~ To which of the following families does mag

belong?

A. the alkaline earth metals
B. the alkali metals
C. the transition metals
D. the representative elements.

69% of naturally occurring copper is copper-63. If only
one other isotope is present in natural copper, what is
it?
A.
B.
C.
D.

When halogens make ions, they tend to:

39. Iron, silver, and mercury are:

A. Lithium-6 is much more abundant
B. Lithium-7 is much more abundant
C. The isotopes are found in roughly equal
abundances
D. The abundance oscillates as neutrons diffuse from
one nucleus to another
33.

'

A. 100 g
B. 180 g
c. 200 g
D. 360 g

How many neutrons are in one atom of the most
common isotope of hydrogen?

c.

The molecular formula for glucose is eJ{ 120 6 •
the mass of one mole of glucose?

copper-61
copper-62
copper-64
copper-65

3


ti. Which of the following has naturally occurring ions

48.

with two different charges?

A.
B.
C.
D.

A. H
B. He

c. v

D. Sr
~

If X represents an alkali metal, and Y a halogen, what is _
the formula for the salt of X andY?

A.
B.
C.
D.
~

In a bond between any two of the following atoms, t
bonding electrons would be most strongly attracted to

49.

Which of the following elements has the largest ator
radius?

A. Cl
B. Ar
C. K

XY

XzY
XYz
The formula depends on X andY

According to periodic trends, which of the following
elements is expected to be the most malleable?

Cl
Cs
He
I

D. Ca
50.

Which of the following has the largest radius?

A.

cr

A. Au

B. Ar

B. Sn

C. K+
D. Ca2+

c. c

D. Cu
51.
44._ The element with the greatest electronegativity is:

A.
B.
C.
D.

Cl
Fr
He
F

A. Al3+ Al s s2B. Al3+: s, A.1: s2c. s Al3+ s2- Al
D.
S2-, 3 Al

s:

r

'45. Which of the following elements is the most

52.

electronegative?

A.
B.
C.
D.

Kr

~Energy of ionization is typically defined as:

'4'1.. Which of the following elements most easily accepts an
extra electron?

A.
B.
C.
D.

Cl
Fr
He
Na

AI <

The attraction of the nucleus on the outermost elect
in an atom tends to:
A. decrease moving from left to right and to:(:
bottom on the periodic table.
B. decrease moving from right to left and toi
bottom on the periodic table.
C. decrease moving from left to right and botton
top on the periodic table.
D. decrease moving from right to left and botton
top on the periodic table.

Be
Br
Cs

A. the energy necessary to remove an electron from an
element in its gaseous state.
B. the energy necessary to remove an electron from an
element in its liquid state.
C. the energy necessary to add an electron to an
element in its standard state.
D. the energy released when an element forms ions in
aqueous solution.

Which of the following is ordered correctly in terrru
atomic radius, from smallest to largest?

53.

The greatest dipole moment is likely to be found

bond where:
A. both bonding elements have high electronegati\
B. both
bonding
elements
have
mode
electronegativity.
C. both bonding elements have low electronegativ
D. one bonding element has high electronegativity
the other has low electronegativity.

'54._ Removing an electron from which of the follm
would require the most energy?
A. Na-

B. Na
C. Na+
D. Na2+


55. An atom of phosphorous will be most similar in size to
which of the following atoms?

62.

Which of the following two elements are in the :
family?

A.

B.
C.
D.

A. CrandFe
B. 0 andSe
C. B andC
D. CeandNd

0
Ge
As
Se

has the smallest density at room temperature?

63.

Which compound listed below is likely to be the
similar chemically to table salt (NaCl)?

A.
B.
C.
D.

A. MgS
B. NaN03
C. AgCl
D. KBr

56. A naturally-occurring sample of which of the following
Aluminum
Magnesium
Sodium
Sulfur

57. A naturally-occurring sample of which of the following

58.

has the smallest density at room temperature?

64.

Removing an electron from which of the folio
would most likely require the most energy?

A.
B.
C.
D.

A.
B.
C.
D.

Beryllium
Boron

Fluorine
Lithium

65. Removing an electron from which of the folio

A naturally-occurring sample of which of the following
has the smallest density at room temperature?

would most likely require the most energy?

A. Cl
B. cfc. H
D. Ca

A. Carbon
B. Fluorine
C. Nitrogen
D. Oxygen
59.

66.

A naturally-occurring sample of which of the following
has the smallest density at room temperature?

A. Argon
B. Chlorine
C. Phosphorus
D. Sulfur
60.

61.

The nucleus of which of the following would exe1
greatest electrostatic force on its outermost electrO!
A. Na
B. H
C. Cl
D. Mg

67.

Lithium's first and second ionization energies are 519
kJ/mol and 7300 kJ/mol, respectively. Element X has a
first ionization energy of 590 kJ/mol and a second
ionization energy of 1150 kJ/mol. Element X is most
likely to be:

A.
B.
C.
D.

Na
Na+
Mg
Mg+

Many chemists consider the electronegativity ofh1
to be undefined. Why?

A. The

small size of helium makes
electronegativity difficult to measure
B. Helium does not have inner-shell electrons
C. Helium atoms are electrically neutral
D. Helium does not form bonds with other eleme1

Oxygen
Sodium
Calcium
Xenon

68.

Which solution is most likely to be colored?

A.
B.
C.
D.

Which of the following elements has· chemical
properties most similar to K?

A. Ca
B. Cs

c. Ar

D. 0

5

Na2C03(aq)
NaCl(aq)
KBr(aq)
FeCh(aq)


UU~

'l.U"\:ILtt..IU.a.J.,;J 1JL& J..T..&...._.L.lL..&.

........,. ..... -~....,--.]

Atom A and Atom B are in the same row of the
periodic table. Atom A has a greater radius than atom
B. Atom A probably also has a greater:

'@) ~s

bond length between a given pair of atom:
mereases:

A. bond strength and bond energy decrease.

'B. bond strength and bond energy increase.

I. Electronegativity

~

IT. First ionization energy

bond strength increases and bond energy decreaseE
D. bond strength decreases and bond energy increaseE

ill. Atomic weight
A.
B.
C.
D.
I.

Ill only
I and Ill
I, II, and Ill
None of the above

"75.._

Because of the ease with which it is oxidized, pure
sodium sometimes catches fire when exposed to water.
Which of the following pure elements is most likely to
catch fire when exposed to water?
A.
B.
C.
D.

A.
B.
C.
D.

bond is:
A. the weak nuclear force. .y

B. the strong nuclear force.
C. electrostatic force.
D. gravitational force.

1. Fe2+ has a higher ionization energy than Fe. Which of
the following is a reasonable explanation for this fact?

7'1,

A. Fe2+ is larger than Fe
B. Fe2+ is isoelectronic with chromium, which has a
higher ionization energy than Fe
C. The outer electrons of Fe2+ experience a greater
effective nuclear charge than those of Fe
D. Energy had to be put into Fe to ionize it to Fe2+

A. Mg2+ has fewer electrons than Na+, and the size of
an ion is determined by the size of its electron
cloud
B. Mg 2+ has a greater mass than Na+, and thus holds
its electrons more tightly

C. Mg2+ has a greater atomic number than Na+, and
thus holds its electrons more tightly
D. Mg 2+ has a smaller ionization energy than Na+, and
thus a smaller size

Molecules
13. How many electrons are in a single covalent bond?

c.

3

~

Two atoms are held together by a chemical bor
because:
A. their nuclei attract each other.

v

'B.. the electrons forming the bond attract each other.
C. their nuclei are attracted to the bonding electrons.
D. the bonding electrons form an electrostatic elm
that wraps and contains both nuclei.
"7S.

2. Mg2+ is smaller than Na+. Why?

D. 4

energy is always released.
S
energy is always absorbed.
energy is absorbed if the bond strength is positive.
energy is released if the bond strength is negative.

~ The force holding two atoms together in a chemic<

Lithium
Beryllium
Magnesium
Potassium

A. 1
B. 2

When a bond is broken:

The distance between two nuclei in a chemical bond
determined by:
A. a balance between the repulsion of the nuclei 1
each other and the attraction of the nuclei for t
""'
bonding electrons.
B. the size of the protons.
C. the size of the neutrons.
D. the size of the electrons.
How does the energy of a typical carbon-carbon doul
bond compare to the energy of a typical carbon-carb
single bond?

A. The bond energy of the double bond is less tl:
that of the single bond
B. The bond energy of the double bond is greater tl:
that of the single bond, but less than twice as gre
C. The bond energy of the double bond is twice t
of the single bond
D. The bond energy of the double bond is more tl
twice as great as that of the single bond


80.

In a water molecule, oxygen has a partial negative
charge because:

87.

A. They are each made from a single element.
B. They exist as a collection of separate and iden
molecules.
C. The relative number of atoms of one elet
compared to another can always be represente
a ratio of two whole numbers.
D. They are held together by intermolecular bond~

A. oxygen is more electronegative than hydrogen
B. oxygen has more valence electrons than hydrogen
C. oxygen is sp3 hybridized
D. water is bent
81.

What is the mass percent of nitrogen in N0 2?
A. 14.0%
B. 20.5%
c. 30.4%
D. 33.3%

82.

88.

Which of the following has the longest bond between
carbon and oxygen?
89.

C. KzC03
D. CH30H
How do the bond lengths in CS3z- compare?
A. two are the same length, the other is longer
B. two are the same length, the other is shorter
C. they are all different lengths
D. they are all the same length
84.

What is the mass of one molecule of water?
A. 18 g
B. 18 amu
C. 18 moles
D. 18 g/mol

A. CO
B. COz

83.

Which of the following is true of all pure compounc

In which of the following compounds does carbon have
the greatest percent by mass?

What is the mass in kilograms of a single v
molecule?
A.

(18)(6.02x1023)(1000)

B.

18
23
(6.02xl0 )(1000)

c.

(18)(1 000)
23
6.02x10

D.

18
23
6.02x10

A. CC4
B. CH30H

90.

C. C3H10H
D. C3H1NH2
85.

A. 50%
B. 75%
c. 80%
D. 92%

Which of the following compounds is not possible?
A. SF6, because fluoride does not have empty dorbitals available to form an expanded octet
B. OC16, because oxygen does not have empty dorbitals available to form an expanded octet
C. H-, because hydrogen forms only positive ions
D. Pb0 2, because the charge on a lead ion is only +2

86.

91.

The mass percent of a compound is as follows: 71
Cl; 24.27% C; and 4.07% H. What is the emp

formula of the compound?
A.
B.
C.
D.

According to VSEPR theory, what is the molecular
geometry of sulfur tetrafluoride?
A.
B.
C.
D.

What is the percent by mass of chlorine in ca
tetrachloride?

Tetrahedral
square planar
seesaw
it depends on the relative electronegativity of
sulfur and fluoride

92.

ClzCHz

The mass percent of a compound is as follows: 71
Cl; 24.27% C; and 4.07% H. If the molecular wei~
the compound is 98.96, what is the molecular for
of the compound?

A.
B.
C.
D.

7

ClCH3
ClCHz
ClCzHs

ClC2Hz
ClCHz
ClzCzlL
Cl3C3Hg


'•

The mass percent of a compound is as follows: 43.64%
P, and 56.36%0. What is the empirical formula of the
compound?
A. PO
B. P02
c. Pz03
D. PzOs

I.

The mass percent of a compound is as follows: 43.64%

P, and 56.36% 0. If the molecular weight of the
compound is 283.88, what is the molecular formula of
the compound?
A.
B.
C.
D.

P203
PzOs
P307
P4010

5. When 7.0 grams of hydrated potassium iodide is
heated, the result is 5.5 grams of anhydrous potassium
iodide. What was the percent by mass of water in the
hydrated potassium iodide?

A. 7.0%
10%
c. 21%
D. 27%

100. Which of the following compounds is 25% nitrogen b:
mass?

A.
B.
C.
D.

NH3
NH(CH3)(CHCH2)
NHzCHzNHCHzNHCH2NHCH3
NO

101. Which of the following compounds is 25% nitrogen b
mole fraction?
A.
B.
C.
D.

NH3
NH(CH3)(CHCH2)
NH2CH2NHCHzNHCHzNHCH3
NO

102. If the mass percent of nitrogen in a compound is 10'
and there are two nitrogen atoms in each molecule c
the compound, what is the molecular weight of tl
compound?
A. 28
B. 70
c. 140
D. 280

B.

6.

Which of the following could be an empirical formula?
A.
B.
C.
D.

Nz04
HzO
N306
Naz(P03)2

17. How many carbons are in 22 grams of C02 ?
A.
B.
C.
D.

11 atoms
0.5 mole
1 mole
2 moles

18. How many nitro gens are in 34 grams ofNH3?

A. 68 atoms
B. 0.5 mole
C. 1 mole
D. 2 moles
)9.

Consider the following reaction:
CzHsOH(l) + 302(g) ~ 2C02(g) + 3H20(g)

If 54 grams of water vapor are produced, how many
moles of hydrogen atoms participated in the reaction?
A. 3
B. 6

c. 9
D. 18

103. What is the empirical formula for benzene (C~6)?
A. CH
B. C2H2

c.

c~6

D. c~12
104. What is the empirical formula
CH3COOH?

A.

of acetic ac:

c~

B. CHzO
C. Cz~Oz
D. CH3COOH
105. The mass percent of a compound is as follows: 6%
and 94% 0. What is the empirical formula of 1
compound?
A. HO
B. H20
c. Hz02
D. H303
106. Which of the following is sufficient for determining ;
molecular formula of a compound?

A. The molecular weight of a compound
B. The percent by mass of a compound
C. The percent by mass and the empirical formula c
compound
D. The percent by mass and the molecular weight c
compound


107. The empirical formula of a hydrocarbon is known to be
CH2. What can be determined from this information?

A. The molar mass and percent composition of the
hydrocarbon.
B. The molar mass of the hydrocarbon, but not its
percent composition.
C. The percent composition of the hydrocarbon, but
not its molar mass.

D. Neither the molar mass nor the percent
composition of the hydrocarbon.

The reaction shown above is NOT an example of a(

'A. combustion reaction.
'B. chemical reaction.
C. oxidation-reduction reaction.
D. physical reaction.

1~.

A. NH3 + OH-----+ ~OH
B. CH30H + 202 ---7 C02 + 2Hz0
C. C~ + OH-----+ CH30H
D. C~ + 20z ---7 C02 + 2H20

Chemical Reactions and Equations
fo~. A 2.0 kilogram block had dimensions 3 em x 5 em x 8
em. What is its density?
A. 1.67 x 10-3 kg/m3

:h,_4.

B. 1.67 kg/m3
C. 167 kg/m3
D. 1.67 x 104 kg/m3

loz

What is the balanced reaction for the combustio:
methane?

Which reaction gives the balanced reaction for
combustion of ethanol (C2H 50H)?
'A~

CzHsOH + Oz ----+ C02 + HzO

'B., CzHsOH + 20z ----+ 2C02 + 2H20
The radius of the Earth's orbit about the sun is 1.5 x 108
km. Which expression could be used to fmd the average
rate at which the Earth travels around the sun in meters
per second?

1\..

C. CzHsOH + 30z ---7 2C02 + 3Hz0
D. 4CzHsOH + 130z ---7 8C02 + 10H20

~\which of the following represents the balanced do
~displacement reaction between copper (IT) chloride

(60)(60)(24)
(2)(3 .14)(1.5 X 108 )(365)

iron (IT) carbonate?

A. CuzCl + FezC0 3 ----+ Cu2C03 + Fe2Cl
B. CuClz + Fe(C03)2 ----+ Cu(C03)2 + FeClz

'(S._ Cu2 Cl + FeC03 ----+ Cu2 C03 +FeCI
D. CuClz + FeC03 ----+ CuC03 -;;- FeClz

8
B. (2)(3.14)(1.5 X 10 )(60)(60)

(1 000)(365)(24)

c.

(2)(3.14)(1.5 X 108 )(60)

(1 000)(365)(24)(60)

~

8
D. (2)(3.14)(1.5 X 10 )(1 000)

The following is an unbalanced reaction:

(365)(24)(60)(60)

C1zHzzOn(/) + Oz(g)----+ COz(g) + HzO(g)
How many moles of oxygen gas are required to 1
one mole of C1zHzzOn?

®Which of the following is a physical reaction?

A. boiling

B. combustion
C. dehydration
D. elimination

A. 1
B. 6
c. 12
D. 24

'n:z. The following is an unbalanced reaction:

1~ Which of the following bonds might be broken in a
physical reaction?

CJI1206(s) + Oz(g)----+ COz(g) + HzO(g)

A. hydrogen bonds
"B. peptide bonds
€. covalent bonds
D. intramolecular bonds

How many moles of oxygen gas are required to 1
one mole ofCJl1z06?

A. 1
B. 3

c.

6

D. 12

9


122. Ten moles of N 20 4(l) are added to an unspecifi,
amount N 2H 3(CH3)(/) according to the equation shov
below:

18. The following is an unbalanced reaction for the
combustion of hexane (Cc;H14):

SN204(l) + 4N2H3(CH3)(/) ~
12H20(g) + N2(g) + C02(g)

How many moles of oxygen gas are required to burn 2
moles ofhexane?

If 23 moles of water are produced and the reaction ru
to completion, what is the limiting reagent?

A. 6
B. 12
c. 14
D. 19

A. N204(l)
B. N2H3(CH3)(/)
C. H 20(g)

D. There was no limiting reagent.

19. The following is an unbalanced reaction:

123. Given the following reaction:

If 2 moles of iron react to completion with 2 moles of
oxygen gas, what remains after the reaction?
which of the following could NOT be true?

A. 1 mole ofFe203 only
B. 1 mole ofFe20 3 and 112 mole of oxygen gas
C. 1 mole ofFe20 3 and 112 mole of iron
D. 1 mole of Fe20 3, 1 mole of iron, and 1 mole of
oxygen gas.

A. 15 moles of nitrogen gas react with 45 moles
hydrogen gas to form 30 moles of ammonia gas.
B. 5 molecules of nitrogen gas react with
molecules of hydrogen gas to form 10 molecules
ammonia gas .
C. 25 grams of nitrogen gas react with 75 grams
hydrogen gas to form 50 grams of ammonia gas.
D. 28 grams of nitrogen gas react with 6 grams
hydrogen gas to form 34 grams of ammonia gas.

.20. The following is an unbalanced reaction:

If 1 mole of Au2S3(s) is reacted with 5 moles of
hydrogen gas, what is the limiting reagent?

A.
B.
C.
D.

124. In the following reaction, which is run at 600 K., '
moles of nitrogen gas are mixed with 11 moles
hydrogen gas:

Au2S3(s)
H2(g)
Au(s)
H2S(g)

The reaction produces 6 moles of ammonia.
many moles of nitrogen gas remain?

l21. Fifteen moles ofN20 4(/) are reacted with N 2H3(CH3)(/)
to produce 36 moles of water via the equation shown
below:

He

A. Omol
B. 1.5 mol
C. 3.0mol
D. 4.5 mol

5N204(l) + 4N2H3(CH3)(/) ~
12H20(g) + 9N2(g) + 4C0 2(g)

125. In the following reaction, which is run at 600 K., ·
moles of nitrogen gas are mixed with 11 moles
hydrogen gas:

How many moles of N 2H 3(CH3)(/) are used up in the
reaction?
A. 4
B. 8
c. 10
D. 12

The reaction produces 6 moles of ammonia. Wha1
the percent yield of ammonia?
A. 42%
B. 57%
c. 82%
D. 100%

10


@Which ofthe following is false?

.26. When the following reaction is run, a 75% yield is
achieved:

A. Crystalline solids have a sharp melting point.
B. Amorphous solids melt over a temperature range.
C. Rapid cooling of polymers is likely to result in

amorphous solid, while slow cooling is more lik(
to form crystals.
D. Any pure compound can be separated into speci
repeating units called molecules.

How many moles of phosphorous trichloride are
required to produce 328 grams ofHCl?

A. 1 mol
B. 2mol

@Which of the following compounds lacks ionic bonds

C. 3 mol
D. 4mol

A. NaCl

B. NaH
C. HCl

l27. The following reaction is run to completion:

D. Ca3(P04)2

P4(s) + 6Cb(g)--+ 4 PCh(l)

133. Which of the following substances forms a molecu
crystalline solid?

How much phosphorous is required to produce 275 g of
phosphorous trichloride?

A.
B.
C.
D.

A. 62g

B. 124 g

c. 248 g
D. 275 g

134. Why are the intermolecular forces in water ice stron1

L28. The following reaction is run to completion:

than the intermolecular forces in dry ice (C02)?
A. Water can exist in the liquid phase at c
atmosphere, while carbon dioxide cannot
B. Water has a much lower molecular weight tl
carbon dioxide
C. Water is polar, while carbon dioxide is nonpolar
D. Water molecules have less kinetic energy tl
carbon dioxide molecules

How much carbon is required to produce 7 5 g of
arsenic gas?

A. 12g
B. 18 g

c.

48g

D. 72g

135. Diamond melts at a much higher temperature tl
water ice. Which of the following is an explanation
this fact?

129. Given the following reaction:

A. Diamond is made entirely of carbon, which i
stronger atom than hydrogen or oxygen
B. Diamond is formed under higher pressure
C. Each atom in diamond is linked to four adjac
atoms by covalent bonds, while in water ice,
links between molecules are weaker hydro!
bonds
D. Diamond is nonpolar, while water is polar

how many moles of oxygen are needed to produce 3.5
moles of sulfur trioxide?
A. l.OOmol

B. 1.75 mol

C. 2.50 mol
D. 3.00mol

Bonding in Solids
1~ Which of the following most accurately describes ice?
A.
B.
C.
D.

diamond
table salt
gold
ice

crystalline solid
amorphous solid
polymer
ionic compound

11


UUJL "'l:_1Jl"""o".a.".a.auo ........_ ..... .- _ _ _ _

------

"

6. Magnesium oxide melts at 2826°C; sodium fluoride

melts at 996°C. Which of the following is a possible
explanation for this fact?

Heisenberg Uncertainty Principle
~In what way is it inaccurate to picture an electron as
~iny particle orbiting a nucleus?

A. Oxygen is more electronegative than fluorine,
creating stronger bonds.
B. The charges on the ions in magnesium oxide are
greater than the ions in sodium fluoride, leading to
stronger ionic bonds.
C. Magnesium oxide exhibits relatively strong dipoledipole bonding, while sodium fluoride exhibits
only van der Waal' s forces.
D. More energy is needed to randomize the crystal
structure of magnesium oxide, because magnesium
and oxygen ions are more massive than sodium
and fluoride ions, respectively.

A. An electron is actually much larger than a

Quantum Numbers

r:z.

typic~

nucleus
B. The electron jumps from orbit to orbit mor
frequently than would be predicted by classic~

mechanics
C. Since it is impossible to know both the positio
and momentum of an electron simultaneously, it i
inappropriate to consider the electron to be
localized particle with a definite orbit
D. It is difficult to determine the precise orb
experimentally

143. Does the Heisenberg uncertainty principle apply

1

macroscopic objects such as basketballs?
How many quantum numbers are necessary to describe
a single electron in an atom?

A. Yes, but the large size of a basketball makes
difficult to determine its position with precisic
anyway
B. Yes, but the large mass of a basketball makes t1
uncertainty in velocity very small even if tl
uncertainty in position is also very small
C. No, because the basketball is made up of ve
many atoms, and the uncertainties cancel out
D. No, because a basketball is constantly interactiJ
with its environment

A. 1

B. 2

c. 3
D. 4

38. Which quantum number designates the shell1evel of an
' electron?
A.
B.
C.
D.

The principal quantum number
The azimuthal quantum number
The magnetic quantum number
The electron spin quantum number

Energy Level of Electrons

~ch of the following is true of the energy levels 1

3~ Which of the following sets of quantum numbers

describes the highest energy electron?

an electron in a hydrogen atom?

A. n=3;l=2;ml=2;ms=-112
B. n=2;l=1;mi=O;ms=-112
C. n=1;l=O;mi=O;ms=-112
D. n = 2; l = 1; m1 = 0; ms = +112

A. Since there is only one electron, that electron ml
be in the lowest energy level
B. The spacing between the n= 1 and n=2 ener
levels is the same as the spacing between the n
and n=5 energy levels
C. The energy of each level can be computed fron
known formula
D. The energy levels are identical to the levels in 1
He+ion

l40. Only one set of the following quantum numbers could
exist. Which set is it?
A. n=3;l=3;ml=2;ms=-112
B. n=2;l=1;ml=2;ms=-112
C. n =4; l= 2; m1=2; ms =-112
D. n = 1; l = 2; m1 = 3; ms = +112

~. Which of the following does not exist?

A. IBr
B. UF6
C. OFs
D. NaLiC0 3

141. What is the maximum number of electrons that can fit
in a shell with principal quantum number 3?

A. 2
B. 3

c. 10
D. 18

12


~·

Monatomic hydrogen gas is placed in a container of
fixed volume, initially at STP. As the temperature is
slowly raised, spectral lines corresponding to electrons
in energy levels above the ground level appear. No
matter how far the temperature is raised, however, no
spectral lines for electrons above the 11 = 7 level are
ever found. Which of the following is a possible
explanation for this phenomenon?

151. What is the electron configuration of iron in the grounc
state?
A. [Ar]4i4~
B. [Ar]3i3~

c.

152. What is the electron configuration of the iodide ion i
the ground state?

A. No elements have electrons in levels above 11 = 7
B. Energy levels above 11 = 7 correspond to orbitals so

A. [Kr]4i 04i 4 5i5p5

large that the hydrogen atoms would overlap,
disrupting the spectral lines
C. At the temperatures required to raise electrons to
orbitals above 11 = 7, hydrogen nuclei would
decompose
D. Beyond 11 = 7, STP cannot be maintained

B. [Kr]3d144d105i5p6
c. [Kr]4d105i5p6
D. [Kr]5i5p 5
153. What is the electron configuration of the

c2+ ion?

A. [Ar]4i3.:f
B. [Ar]4s23i
c. [Ar]4i3d7
D. [Ar]3Jl

17. An electron in a certain element can have energies of
-2.3, -5.1, -5.3, -8.2, and -14.9 eV. -14.9 eV is the
ground state of the electron, and no other levels exist
between -14.9 and -2.3 eV. Which of the following
represents a partial list of photon energies that could be
absorbed by an electron in the ground state of this
atom? All energies are in electron volts.

154. Which of the following represents an excited state of a

atom?
A.
B.
C.
D.

A. -2.3, -5.1, -5.3, -8.2, -14.9
B. 0.2, 2.8, 2.9, 6.7

c.

[Ar]3i4~

D. [Ar]3~4s 2

2.3, 5.1, 5.3, 8.2, 14.9

1s22s23s 1
1i2i2p 1
1i2i2p6
1s22i2p63s 1

D. 6.7, 9.6, 9.8, 12.6, 15.0, 16.1
155. Which of the following electron configurations coul
represent an excited state of an atom?

18. Suppose an element in its ground state is capable of
absorbing photons with energy 2.3 eV and 4.1 eV, but

A.

B.
C.
D.

no other intermediate energies. If the atom in its ground
state absorbs a photon of energy 4.1 eV, it is found to
sometimes later emit a single photon of 4.1 eV, but
sometimes it emits a photon with energy:
A.
B.
C.
D.
~9.

1.8eV

156. Which of the following electron configurations coul
represent an ion?

2.0 eV
2.3 eV
4.1 eV

I. 1i2i2p6

n. 1i2i2p63i
m. 1i2i2l3i3cf3p6

If a sulfur atom IS m its ground state, how many
unpaired electrons does it have?

A. Ionly
B. I and II only
C. II and ill only
D. I, II, and ill

A. 0
B. 1

c.

1i2i2p63i3i 0
1i2i2p63i3p64s 1
1i2i2l3i3J3p64i
1s22i2p63i3p63d104i4p6

2

D. 4

157. Suppose electrons could have three possible spin stat1
(up, down, and sideways), rather than just tw·
Assuming nothing else was different, which of tl
following would be the correct ground state electrc
configuration for an element with atomic number 16?

50. What is the electron configuration of a bromine atom in
the ground state?
A. 1i2i2p63i3l3i 04i4d104p5
B. 1i2i2p6 3i3p64i4i 04p5

C. 1i2s22p63i3p63d104i4p 5

A.
B.
C.
D.

D. 1i2s22p63i3l4s24/

13

1s2 1p62s22p6
1i2i3i3l4i4p2
1s32s32/3s 1
3s23p63d'


·u~

""'-.,!U."'..,. .........,.II..&l,:J'

.&.11..&

. . . . . - . . -... - . -

--------J
~· In an ideal gas, which of the following shows the

ases

relationship between pressure and volume at constant
temperature?

. Which of the following is/are assumed in the kineticmolecular theory of ideal gases?

A.

I. The molecules of gas all move at the
same speed
II. The molecules of gas all have negligible
volume
ill. The molecules of gas exert no attractive
forces on each other

c.

v-.

A. Ionly
B. I and ill only
C. I1 and m only
D. I, 11, and ill

B.

D.

!_)

. In the ideal gas law, what does the variable V represent?

A. The average speed of a gas molecule
B. The average velocity of a gas molecule
C. The volume of a gas molecule
D. The volume of the container which holds the gas

@)Container A contains gas at 300°C. Container B
contains the same gas, but at 150°C. Which of the
following is a true statement?

I. Which of the following affects the average force (per
unit area) exerted by a gas on the wall of its container?

'-

A. All of the gas molecules in container A move faster
than all of the gas molecules in container B.
B. All of the gas molecules in container A move
slower than all of the gas molecules' in container B.
C. Each of the gas molecules in container A has more
mass than each of the gas molecules in container B.
D. None of the above statements are true.

I. The average speed of a gas molecule
II. The frequency of collisions between gas
molecules and the wall
m. The volume of a gas molecule

A. Ionly
B. I1 only
C. I and I1 only

D. I, IT, and ill

®A gas initially fills a 2.0 Lcontainer. Heat is then added
''to the gas, raising its temperature from 300 K to 450 K,
and increasing its pressure from 1.0 atm to 1.5 atm.
What is the new volume of the gas?

In an ideal gas, which of the following shows the
relationship between pressure and temperature at
constant volume?

A. 1.3 L
B. 2.0L
C. 3.0 L
D. 4.5L

c.

A.

t

p

~

t

p

-\at a pressure of 820 torr and a temperature of 300 K
How many moles of gas are inside the balloon? (R =
0.08206 L atm mor 1 K 1)

r-.

T-.
B.

~

~A balloon has a volume of 500 mL when filled with ga!

A. 0.022
B. 0.22
c. 2.2
D. 22

D.

t

p

/

T-.

t

p

_)
r-.
14


@A balloon initially contains 20 grams of helium at a
pressure of 1000 torr. After some helium is let out of
the balloon, the new pressure is 900 torr, and the
volume is half of what is was. If the temperature has
not changed, how much helium is now in the balloon?

170. A researcher wishes to use two identical containers,
to store 5 moles of oxygen, and one to store 3 mole:
nitrogen. Both are kept at 300 K and 5 atm. Is
possible?
A. Yes, since oxygen and nitrogen have diffe1
molar masses
B. Yes, since these conditions are not STP
C. No, because once pressure, volume,
temperature of an ideal gas are known, the nurr
of moles is determined
D. No, because number of moles and temperature
directly proportional

A. 9 grams
B. 10 grams
C. 11 grams
D. cannot be determined from the information given

167. Argon is the most common noble gas in the atmosphere
at the surface of the Earth, despite the fact that helium
is much more common in the universe. Why?

171. An ideal gas is placed in a 3.0 L container wit
piston. The pressure of the gas is initially 850 torr. F
much additional pressure must be exerted on the pif
in order to lower the volume of the container to l.C

A. Argon is a byproduct of the decay of radioactive
xenon in the Earth's crust
B. Argon is the most stable of the noble gasses
C. The production of argon is catalyzed by
greenhouse gases
D. Argon has a similar density to nitrogen, the major
component of the atmosphere

Assume the temperature of the gas does not change.

A.
B.
C.
D.

168. A researcher wishes to have two 20.0 L chambers
containing equal amounts (moles) of oxygen gas, one at
5 atm and the other at 3 atm. Is this possible?

283 torr
850 torr

1700 torr
2550 torr

172. Gas A is at 25°C and 1 atmosphere. If the pressut
increased to 3 atmospheres without changing
volume, the new temperature will most likely be:

A. Yes, if the oxygen samples in the containers have
different densities
B. Yes, if the oxygen samples in the containers are at
different temperatures
C. No, because once the volume and the number of
moles of an ideal gas are known, all other
parameters are determined
D. No, because volume and pressure are inversely
proportional for an ideal gas

A. -174°C
B. 8.3 °C

c. 28 oc
D. 621°C

173. An ideal gas with pressure 2 atmospheres is expar
to twice its initial volume. What is the new pressure'
A.
B.
C.
D.

169. A researcher wishes to have two samples of oxygen gas
with the same pressure, volume, and temperature, but
with different densities. Is this possible?
A. Yes, because density is not given in the ideal gas
law.
B. Yes, if different isotopes of oxygen are used.
C. No, because once pressure, volume, and
temperature of an ideal gas are known, all other
parameters are determined
D. No, because density is inversely proportional to
volume

1 atm
2 atm
4atm
Cannot be determined from the information giv

174. Which of the following could be used to estimate
value of absolute zero?
A. Plot pressure vs. temperature values for an i
gas at constant volume, and extrapolate
resulting line to low temperatures. The inter
with the temperature axis is an estimate of absc
zero.
B. Plot volume vs. temperature values for an ideal
at constant pressure, and extrapolate the resul
line to low temperatures. The intercept with
temperature axis is an estimate of absolute zero
C. Allow both volume and pressure to vary, and
the product of pressure and volume

temperature. The intercept with the tempen
axis is an estimate of absolute zero.
D. All of the above techniques would work

15


179. Consider the synthesis of ammonia from its constituerr

5. 50.0 grams of oxygen are placed in an empty 10.0 liter
container at 28°C. Compared to an equal mass of
hydrogen placed in an identical container (also at
28°C), the pressure of the oxygen is:

elements:

Which of the following expressions can be used to fine
the number of grams of ammonia that can be producec
from 24.5 mL of hydrogen at STP, if the percent yielc
is 35%?

A. Less than the pressure of the hydrogen

B. Equal to the pressure of the hydrogen
C. Greater than the pressure of the hydrogen
D. Cannot be determined from the information given
6. Container A and B both contain 1.00 L of a gas at STP,

A.

but container A contains oxygen, while container B
contains nitrogen. Assuming the gases behave ideally,
the gases has the same:

(0.001)(24.5)(2/3)(17.0)(0.35)
22.4

B.

(0.001 )(24.5)(2/3)(17.0)
(22.4)(0.35)

c.

(1 000)(24.5)(2/3)(17.0)(0.35)
22.4

D.

(1 000)(24.5)(2/3)(17.0)
(22.4)(0.35)

I. number of molecules
density
kinetic energy

n.
m.

A. II only

B. illonly
C. I and ill only
D. I, II, and ill

180. A sealed container initially contains solid carbon an1

pure oxygen gas. In the presence of a spark, all of th
carbon is converted into a gas with density 1.25 giL a
STP. What is the identity of the gas?

7. A container appears to be marked ''Ne, 3.5 moles," but

has no pressure gauge. By measuring the temperature
and checking the volume of the container, the scientist
uses the ideal gas law to estimate the pressure inside the
container. Unfortunately, the handwriting on the
canister is difficult to read, and the container actually
contains 3.5 moles of He, not Ne. How does this affect
the scientist's estimate of the pressure inside the
container?

A.

c2

B. CO
C. C02
D. Cannot be determined from the information given
181. When methane gas and oxygen gas are made t

undergo combustion in a sealed container, and th
temperature brought back to the original temperature, :
is found that the pressure has not changed. Which c
the following is consistent with the data?

A. The estimate is too low
B. The estimate is too high
C. The estimate is correct, but only because both
gases are monatomic
D. The estimate is correct, because the identity of the
gas is irrelevant

A. Methane was initially in excess; the products of th

reaction were carbon monoxide and water vapo:
and some of the methane did not react
B. Methane and oxygen were present in amounts sue
that both were entirely consumed, producin
carbon monoxide and water vapor
'
C. Oxygen was initially in excess; the products of th
reaction were carbon dioxide and water vapor
D. Oxygen was initially in excess, the products of th
reaction were carbon dioxide, hydrogen gas, an
ozone

'8. A container contains only oxygen, nitrogen, carbon
dioxide, and water vapor. If, at STP, the partial pressure
of oxygen is 200 torr, carbon dioxide 10 torr, and water
vapor 8 torr, what is the partial pressure of the

nitrogen?
A. 14 torr
B. 542 torr
C. 760 torr
D. 782 torr

182. If 64.0 grams of oxygen gas at 5.0 atm pressru
occupies 3.0 L, what is the temperature of the gas? (R
0.08206 L atrnlmol K)

A. 3K
B. 91 K
C. 298 K
D. Cannot be determined from the information given.

16


183. The mole fraction of nitrogen in air is approximately
0.8. At STP, what is the partial pressure of nitrogen in
air?
A.
B.
C.
D.

190. A 5 Newton weight is placed on a piston with an
centimeter radius. The piston compresses helium i.J
sealed container until the piston stops moving beca
of the increase in pressure inside the container. 1

pressure in the container is now recorded. Some heli
is then removed from the container, causing the pis
to fall so that the volume of the container drops
25%, at which point the gas can again support
piston, and the pressure is again recorded. How do
two recorded pressures compare?

608 torr
760 torr
800 torr
Cannot be determined from the information given

184. If the partial pressure of hydrogen in a container held at
5 atmospheres pressure is 35 torr, what is the mole
fraction of hydrogen in the container?

A. Since pressure and volume are direc
proportional, the second pressure is lower.
B. Since pressure and volume are invers
proportional, the second pressure is higher.
C. Since the force on the piston is constant,
pressures are the same.
D. There is not enough information to answer 1
question.

A. 0.009
B. 0.046
c. 0.23
D. Cannot be determined from the information given
185. If the partial pressure of carbon dioxide is 30 torr at

STP, what is the mass of the carbon dioxide present?
A. 0.04 grams
B. 1.7 grams
C. 44 grams
D. Cannot be determined from the information given

191. Which of the following formulas gives the kin'
energy of n moles of gas?

A. 1/211tV2, where m is the molar mass of the gas

186. If the partial pressure of carbon dioxide is 30 torr at
STP, what is the percent by mass of carbon dioxide?
A. 1.7%
B. 4%
c. 44%
D. Cannot be determined from the information given
187. If the partial pressure of carbon dioxide is 30 torr at
STP, and nitrogen is the only other gas present, what is
the percent by mass of carbon dioxide?

192. Which of the following would be a good method
distinguishing between ordinary hydrogen
deuterium (a rare isotope of hydrogen)?

A. 4%
B. 6%
c. 61%
D. Cannot be determined from the information given

I. Measure the density of the gas at STP
II. Measure the rate at which the gas effuses
ill. Determine the number of grams of gas that '
react with one mole of oxygen to form watet

188. If the partial pressure of carbon dioxide is 30 torr at
STP, the gas is 10% carbon dioxide by mass, and there
is only one other species of gas present, which of the
following could be the other species of gas?
A.
B.
C.
D.

l

Vis the volume of the container
B. 3/2 nRT, where n is the number of moles of gas
is the ideal gas constant, and T is the absol
temperature
C. nPA, where n is the number of moles of gas, 1
the total pressure, and A is the surface area of
container walls
D. 1/2 nPA, where n is the number of moles of gas
is the total pressure, and A is the surface area of
container walls

A.
B.
C.

D.

Hydrogen
Methane
Oxygen
Chlorine

None of the above
II only
illonly
I, II, and ill

193. What is the ratio of the average speed of an atom
neon to a molecule of hydrogen at the same temperat
and pressure?

189. In an 11.2 liter container the partial pressure of nitrogen
gas is 0.5 atmospheres at 25°C. What is the mass of
nitrogen in the container?

A. 1:10
B. 1:3.2
c. 3.2:1
D. 10:1

A. 3.5g
B. 7g
c. 14g
D. 28g
17

uv...a.

~

.......... ..,. .........,..._.U' · - ............ _ .... __

-------J

:l. What is the ratio of the average speed of an atom of
neon to another atom of neon at twice the temperature
but the same pressure?

200. The average speed of the molecules in a sample o:
carbon dioxide is found to be the same as that of l
sample of neon. How do the temperatures of th<
samples compare?

A. 1:1
B. 1:1.4
c. 1:2
D. 1:4

A. The temperature of the carbon dioxide is roughl~
two times the temperature of the neon
B. The temperature of the neon is roughly two time
the temperature of the carbon dioxide
C. The temperatures of the two gases are the same
D. Cannot be determined from the information given

5. What is the ratio of the average speed of an atom of
neon to another atom of neon at the same temperature
but twice the pressure?

Use the following information to answer questions 201-204
A cotton ball moistened with ammonia and a cotton bal
moistened with aqueous HCl solution are inserted int•
either end of a glass tube 10 em long. HCl and NH3 ga
move through the test tube. Where the gases meet, a circl
of ammonium chloride precipitates inside the tube.

A. 1:1
B. 1:1.4
c. 1:2
D. 1:4
·6. If an equimolar mixture of oxygen, nitrogen, krypton,
and carbon dioxide are placed in a 10 L container with
a one-micron (0.001 mm) wide hole in the side, so that
the gases slowly leak out, which gas will predominate
after 20% of the original gases have leaked out?

Cotton ball
withHCl

A. Oxygen
B. Nitrogen
C. Krypton
D. Carbon dioxide

Air
10cm

40% more time to diffuse the same distance as neon.
What is the molecular formula of the gas?

A. 1:1
B. 1:1.5
c. 1.5:1
D. 36:17

A. CRt
B. CzHz
C. C3H3
D. CJ-4

kbNa
kJ.Na

C.

Na~
~+Na

D.
~9.

202. The movement of gas in this experiment is called:

Which of the following is equivalent to the ideal gas

law constant, R? Ckt, is Boltzmann's constant and NA is
Avogadro's number)
A.
B.

------------~

201. What is the approximate ratio of the average speed c
the HCl gas molecules compared to the average spee
of the NH3 gas molecules?

17. A gas with empirical formula CH is found to take about

•s.

Cotton ball
withNH3

A.
B.
C.
D.

diffusion
effusion
extrusion
natural transport

203. The HCl molecules in this experiment don't follow
straight line, but follow a path more closely resemblir

that shown in the diagram. Why?

The average molecular kinetic energy of a sample of
carbon dioxide is found to be the same as that of a
sample of neon. How do the temperatures of the
samples compare?

A. The natural spinning and rotation ofHCl molecul•
causes them to change directions.
B. The HCl molecules bump into air molecules.
C. The HCl molecules bump into NH3 molecules.
D. Any gas molecule, if acted upon by no outsi<
forces, will follow a mean free path resembling t1
one shown in the diagram. This is called Brownil
motion.

A. The carbon dioxide is at roughly four times the
temperature of the neon.
B. The neon is at roughly four time the temperature of
the carbon dioxide.
·
C. The temperatures of the two gases are the same.
D. The temperatures cannot be determined from the
information given.

18


204. How far from the left end of the glass tube will the
precipitate form?

206. Which of the following :i:night represent a serie!
readings taken from gauge 2 during the effusion •
sample from the glass bulb?

A. 2cm
B. 4cm
C. Scm
D. 6cm

c.

A.

t

t

p

p

Questions 205-208 refer to the apparatus shown below. A
small pinhole is located between Stopcocks A and B.

time --..

time --..

D.

B.

t

t

p

p

time --..

time --..

207. Under ideal conditions, which of the following w<
affect the effusion rate of the sample gas in the g
bulb?
I. The molecular weight of the sample gas
IT. The pressure difference as measured by
Gauge 1 and2
m. The size of the gas molecules

205. Stopcock B is closed. A gas sample is introduced into
the glass bulb through an open Stopcock C. Stopcock
C was then closed and the vacuum pump is turned on.
In order to find the rate of effusion for a gas sample in
the glass bulb, which of the following is true?

A. Ionly

B. II only
C. I and II only
D. I, II, and III

A. Readings should be taken from gauge 1 at regular
intervals with stopcocks A and B closed.
B. Readings should be taken from gauge 1 at regular
intervals with stopcocks A and B open.
C. Readings should be taken from gauge 2 with
stopcocks A and B closed.
D. Readings should be taken from gauge 2 with
stopcocks A and B open.

208. The apparatus was used to test the rates of effusio1
H 2 , He, N 2 gases. Which of the following graphs n
accurately reflects the results as measured by Gauge

c.

A.

···································
p
time __..

time --..

D.

B.

t ~-~··. . . . . . . . . . . . . . . N2
p

'

' ' ....

H2
'----He

time --..

19

t :~· ·'· ·....· ..... .-.--__
·················

p

time __..


1001 Questions in MCAT Chemistry
Refer to the graph below to answer questions 213-219. Th(
graph below shows PV/RT versus pressure for 1 mole o:
several gases at 300 K.

Real Gases
209. Which of the following gases, when compared under

identical conditions, is likely to be least ideal?
A. 02

B. 03
C. C02

D. CH3 0H
210. As the volume of a container is decreased at constant
temperature, the gas inside begins to behave less
ideally. Compared to the pressure predicted by the ideal
gas law, the actual pressure is most likely to be:

A. Lower, due to the volume of the gas molecules
B. Lower, due to intermolecular attractions among gas
0

molecules
C. Higher, due to the volume of the gas molecules
D. Higher, due to intermolecular attractions between
gas molecules

400
.600
P(atm)

800

213. At 100 atm, C02 deviates from ideal behavior.
direction of this deviation is best explained by:

211. As the temperature of a sample of gas is decreased at
constant volume, the gas inside begins to behave less
ideally. Compared to the pressure predicted by the ideal
gas law, the actual pressure is most likely to be:

Th

A. molecular volume
B. intermolecular attractions
C. temperature

D. molecular shape

A. Lower, due to the volume of the gas molecules
B. Lower, due to intermolecular attractions among gas

214. At extremely high pressures, all gases deviate from th
ideal gas law in the same direction. The greate~
contributing factor to this deviation is:

molecules
C. Higher, due to the volume of the gas molecules
D. Higher, due to intermolecular attractions between
gas molecules

A. molecular volume
B. intermolecular attractions
C. temperature
D. molecular shape

212. Which of the following explains the pressure and
volume deviations in a real gas compared to an ideal
gas?

215. Deviations from ideal behavior typically increase wit
which of the following molecular characteristics?

I. Ideal gas molecules don't have volume
and real gas molecules do.
II. Ideal gas molecules don't exert forces
on one another and real gas molecules
do.
ill. Ideal gas molecules all move at the
same speed for a given temperature,
whereas the speed of real gas molecules
varies within a sample of gas at a given
temperature.

A. molecular mass only
B. molecular complexity only
C. molecular mass and complexity
D. Deviations from ideal behavior depend upo
temperature and pressure and are independent c
molecular characteristics.
216. According to the graph, at what pressures of C02 is tb
ideal gas law correct and the proportionality constant _
equal to 0.08206 L atm K-1 mor1?

A. I only
B. II only

C. I and II only
D. I, II, and III

A.
B.
C.
D.

0 atm and 500 atm
75 atm
500 atm
830 atm

20
Copyright© 2005

200

Exam Kroeker'S, Inc.


Gases, Kinetics, and Chemical Equilibrium
217. According to the graph, which of the following would
be true, if the ideal gas law, PV = nRT, were used to
calculate the volume of a sample of CE14 gas from
measured variables at 200 atm and 300 K and again at
600 atm and 300 K?

220. Which of the following gives the temperatures in
increasing order?

A.
B.
C.
D.

A. The calculated volume would be less than the real
volume for both calculations.
B. The calculated volume would be greater than the
real volume for both calculations.
C. The calculated volume would be less than the real
volume for the 200 atm sample and greater than the
real volume for the 600 atm sample.
D. The calculated volume would be greater than the
real volume for the 200 atm sample and less than
the real volume for the 600 atm sample.

221. At which temperature does the behavior of nitrogen
most resemble that of an ideal gas?

A.
B.
C.
D.

T1
Tz
T3
The behavior of nitrogen resembles an ideal gas at
all three temperatures.

222. If 2 moles of nitrogen had been used instead of 1 mole,
what would be the approximate value of PVIRT at T1
and 600 atm?

218. The data graphed for C02 actually pertain to a
temperature of 313 K. The best explanation for this is:
A.
B.
C.
D.

T1 < TzT3TzT1 < T3 < T2

C02 liquefies under low pressure at 300 K.
C0 2 liquefies under high pressure at 300 K.
At 300 K C0 2 behaves like an ideal gas.
At 300 K C02 deviates from ideal behavior.

A. 1

B. 2

c. 3
D. 4

219. Which of the following is indicated by the graph?

223. Based on the graph, which of the following properties
of the nitrogen molecules plays the greatest role in
explaining the deviation from ideal behavior for
nitrogen gas at high temperatures?

A. If temperature is sufficiently low, deviations due to
molecular attractions dominate.
B. If temperature is sufficiently low, deviations due to
molecular volume dominate.
C. If pressure is sufficiently high, deviations due to
molecular attractions dominate.
D. If pressure is sufficiently high, deviations due to
molecular volume dominate.

A.
B.
C.
D.

polarity
molecular volume
intermolecular attractions
The answer cannot be deduced from the graph.

Use the van der Waals equation given below to answer
questions 224-227. The van der Waals equation is used to
predict the behavior of real gases. a and b are constants
specific for a particular gas. Their values can be obtained by
experiment or from a reference book.

Refer to the graph below to answer questions 220-223. The
graph below shows PVIRT versus pressure for 1 mole of
nitrogen gas at three different temperatures Th T2 , and T3.
3~------~------~------~------.

2

(P+ ~~) (V- nb) =nRT
./

/!r'

2~------~----~~~-~--+-----~

'

PV
RT

:/ _,(

1 ..

0

van der Waals Equation

~ T3

224. The van der Waals constants a and b tend to increase
when which of the following changes are made to the
gas molecules?

~---..~·

300

600
P(atm)

A. Increasing both molecular mass and structural
complexity
B. Decreasing both molecular mass and structural
complexity
c. Increasing molecular mass but decreasing
structural complexity
D. Decreasing molecular mass but increasing
structural complexity

900

21


1001 Questions in MCAT Chemistry
229. If the rate law for a reaction is:

225. The constant a and b have positive values. What is the
expected difference between using the ideal gas law,

PV = nRT, to calculate the pressure from measured
variables, and using van der Waals equation to calculate
pressure from measured variables?

Rate= k[Af[Bt
what is the order of the reaction?

A. 2
B. 3
c. 4
D. 6

A. The pressure will always be lower when calculated
with van der Waals equation.
B. The pressure will always be greater when
calculated with van der Waals equation.
C. The pressure will always be the same when
calculated with van der Waals equation.
D. Whether the value for pressure is lower or greater
when calculated with van der Waals equation will
depend upon the real volume and temperature.

230. If the rate law for a reaction is:

Rate= k[A][B] 2
what is the order of the reaction?
A. 2
B. 3
c. 4

226. Which of the following would be expected to have the
greatest value for a and b?

D. 6

A. He
B. Ne
c. Ar
D. Kr

231. If the rate law for a reaction is:

Rate= k[Af[Bt
what is the order of A in this reaction?

227. Which of the following is true concerning the constants
a andb?

A. 2
B. 3
c. 4

A. A large value for a indicates strong intermolecular
attractions, and a large value for b indicates a large
molecular volume.
B. A large value for a indicates weak intermolecular
attractions, and a large value for b indicates a small
molecular volume.
C. A large value for b indicates strong intermolecular
attractions, and a large value for a indicates a large

molecular volume.
D. A large value for b indicates weak intermolecular
attractions, and a large value for a indicates a small
molecular volume.

D. 6
232. The rate law for a reaction is:

Rate= k[A] 2

If B is also a reactant, what is the order of B in this
reaction?

A. 0
B. 1

c. 2
D. Cannot be determined from the information given
233. Which of the following methods could be used to
determine the rate law for a reaction?

Kinetics

I. Measure the initial rate of the reaction
for a variety of reactant concentrations
II. Graph the concentration of the reactants
as a function of time
ill. Find the mechanism of the reaction

228. Consider the complete combustion of ethanol (C 2H 60)

to form carbon dioxide and water. If the ethanol is
consumed at a rate of 2.0 M s-\ what is the rate at
which carbon dioxide is produced?

A.
B.
C.
D.

l.OMs- 1
2.0Ms- 1
4.0Ms- 1
Cannot be determined from the information given

A.
B.
C.
D.

22

I only
III only
II and III only
I, II, and III


Gases, Kinetics, and Chemical Equilibrium
Questions 237-242 depend on the following mechanism for
the conversion of2-iodo-2-methylpropane into an alcohol:

234. Consider the dissociation of hydrogen gas:

2-iodo-2-methylpropane ~
2-methylpropane cation + iodide

Rates were measured for a number of different
concentrations:

2-methylpropane cation + water ~
protonated 2-methylpropanol

Rate/M s-1

[H2]
1.0
1.5
2.0

1.2 X 104
2.7 X 104
4.8 X 104

protonated 2-methylpropanol + water ~
2-methylpropanol +hydronium
237. In the mechanism shown, iodide is a(n):

What is the rate law for this reaction?

A.

B.
C.
D.

A. Rate = k[Hz]
B. Rate = k[Hzf
C. Rate= k[Hf/[Hz]
D. The rate law cannot be determined from the
information give_n

238. In the mechanism shown, 2-methylpropane cation is
a(n):

235. Consider the reaction

A.
B.
C.
D.

2Hz+ 2NO ~ Nz + 2Hz0
Rates were measured for a number of different
concentrations:

[H2]
0.1
0.2
0.3
0.2

[NO]

Rate/M s-1

0.3
0.3
0.1
0.1

230
460
80
50

A.
B.
C.
D.

Reactant
Product
Intermediate
Catalyst

240. In the mechanism shown, hydronium is a(n):
A.
B.
C.
D.

Rate=k[H2][NO]
Rate=k[H2][N0]2
Rate=k[Hzf[NO]
Rate=k[H2f[N0] 3

Reactant
Product
Intermediate
Catalyst

241. Which of the following is the correct net equation for
the reaction shown above?

236. Suppose a certain reaction has the rate law:
Rate= k[A] 112 [B]

A. 2-iodo-2-methylpropane ~ 2-methylpropanol

Which of the following can be concluded about the
reaction?
A.
B.
C.
D.

Reactant
Product
Intermediate
Catalyst

239. In the mechanism shown, water is a(n):

II

What rate law is most consistent with this data?
A.
B.
C.
D.

Reactant
Product
Intermediate
Catalyst

B. 2-iodo-2-methylpropane ~
2-methylpropanol + hydronium

Two molecules ofB react for every molecule of A
Two molecules of A react for every molecule ofB
B reacts at twice the rate of A
This reaction does not take place in a single step

C. 2-iodo-2-methylpropane ~
2-methylpropanol + iodide
D. 2-iodo-2-methylpropane + 2H20 ~
2-methylpropanol + iodide + hydronium

23
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