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Question, hints, and answers.
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1. Based on intermolecular forces, which of these substances would
have the highest boiling point? (1 point) *hint HYDROGEN BONDS
= strong intermolecular force, stronger intermolecular force = higher
boiling point
a
.
b
.
H
e
C
H
4
c
.
O
2
d
.
N
H
3
2. A gas occupies a volume of 444 mL at 273 K and 79.0 kPa. What is
the final kelvin temperature when the volume of the gas is changed
to 1880 mL and the pressure is changed to 38.7 kPa? (1 point)
*hint use combined gas law equation P1V1/T1 = P2V2/T2
a
.
b
.
c
.
d
.
31.
5K
29
2K
56
6K
23
60
K
3. Which substance is correctly paired with its type of bonding? (1
point) *hint 0.4 - 1.7 polar covalent less then 0.4 is nonpolar. Beyond
2.0 is ionic. Also look at structure. NH3 has a unshared pair on top
a
.
b
.
c
.
NaBr - nonpolar
covalent
HCl - nonpolar
covalent
Br2 - polar covalent
d
.
NH3 - polar covalent
4. Which pair of formulas correctly represents a molecular formula
and its corresponding empirical formula? (1 point) *hint look for
proportional ratios
a
.
b
.
c
.
d
.
C2H2 and
CH
C3H4 and
CH2
C4H6 and
CH
C5H8 and
C2H2
5. The nucleus of an atom of cobalt-58 contains (1 point) *hint look at
periodic table and at atomic number/atomic mass. Atomic number is
protons/electrons. Atomic mass is protons + neutrons.)
a
.
27 protons and 31
neutrons
b
.
c
.
d
.
27 protons and 32
neutrons
59 protons and 60
neutrons
60 protons and 60
neutrons
6. Which quantity of particles is correctly represented by the formula
H2SO4? (1 point) *hint remember Avogadro, 1 (mole) of anything same
# (Avogadro’s #)
a
.
b
.
c
.
1.0 mole of ions
1.0 mole of
molecules
6.02 x 1023 ions
d
.
6.02 x 1023 atoms
7. One mole of O2 has approximately the same mass as one mole
of (1 point) *hint (Oxygen is a diatomic, O2 is 32g)
a
.
C
H
4
b
.
c
.
d
.
S
L
i
H
C
l
2
8. Which electron configuration represents the electrons of an atom
in an excited state? (1 point) *hint the rule for filling up each energy
level is 2n^2, so its 2-8-18 …, in excited state an electron moves up or
down)
a
.
2-81
b
.
8
c
.
d
.
2-86
2-817-6
2-818-5
9. Which properties are most common in nonmetals? (1 point)
*hint nonmetals tend to gain electrons more often and often you need a
higher energy to remove an electron from it. Definition of
electronegative and ionization energy.
a
.
b
.
low ionization energy and low
electronegativity
low ionization energy and high
electronegativity
c
.
high ionization energy and low
electronegativity
d
.
high ionization energy and high
electronegativity
10.
What is the total number of electrons found in an atom of
sulfur? (1 point) *hint look at atomic number
a
.
6
b
.
8
c
.
1
6
d
.
3
2
11.
Which ion has the largest radius? (1 point)
*hint elements more to the left and down are bigger (atomic radius
decreases to the right of a period or up a group)
a
.
N
a
+
b
.
K
+
c
.
M
g
2
+
d
.
C
a
2
+
12.
Pure silicon is chemically classified as a metalloid because
silicon (1 point) *hint metalloid has both metal/nonmetal
characteristics
a
.
b
.
c
.
is malleable and ductile
is an excellent conductor of heat and
electricity
exhibits hydrogen bonding
d
.
exhibits metallic and nonmetallic properties
13.
The forces between atoms that create chemical bonds are the
result of interactions between (1 point) *hint think of an atom
a
.
nuclei
b
.
electrons
c
.
protons and
electrons
d
.
protons and
nuclei
14.
Which molecule has an asymmetrical shape? (1 point)
*hint visualize the lewis dot structure of each of these. Which of these
are NOT symmetrical. Which has unshared electrons
a
.
N
2
b
.
C
l
2
c
.
N
H
3
d
.
C
C
l
4
15.
What happens when NaCl(s) is dissolved in water? (1 point)
*hint oxygen (-) (oxygen anion) likes Na (+) (cation)
a
.
b
.
c
.
d
.
Cl- ions are attracted to the oxygen atoms of water
molecules.
Na+ ions are attracted to the oxygen atoms of water
molecules.
Cl- ions are repelled by the hydrogen atoms of water
molecules.
Na+ ions are repelled by the oxygen atoms of water
molecules.
16.
When compared with the energy of an electron in the first
shell of a carbon atom, the energy of an electron in the second
shell of a carbon atom is (1 point) *hint increase in potential energy
as you go up shells
a
.
b
.
c
.
less
great
er
the
same
17.
Which set of symbols represents atoms with valence
electrons in the same electron shell? (1 point) *hint look at elements
in same group
a
.
b
.
c
.
Ba, Br,
Bi
Sr, Sn,
I
O, S,
Te
d
.
Mn, Hg,
Cu
18.
The formula H2O2 is an example of (1 point) *hint this is not in
the lowest ratio
a
.
b
.
c
.
d
.
a molecular
formula
an empirical
formula
an ionic formula
an organic
formula
19.
Which radioisotope undergoes beta decay and has a half-life
of less than 1 minute? (1 point) *look in reference table for the decay
rate of each
a
.
b
.
c
.
d
.
Fr22
0
K42
N16
P32
20.
Experiments performed to reveal the structure of atoms led
scientists to conclude that an atom's (1 point) *hint modern atomic
theory
a
.
b
.
c
.
positive charge is evenly distributed throughout its
volume
negative charge is mainly concentrated in its nucleus
mass is evenly distributed throughout its volume
d
.
volume is mainly unoccupied
21.
Which process represents a chemical change? (1 point)
*hint chemical change means you cant go back to original state by
physical methods. When you melt ice or evaporate water its still
the same thing. (physical changes)
a
.
b
.
c
.
d
.
melting of ice
corrosion of
copper
evaporation of
water
crystallization of
sugar
22.
Which type of radiation continues in a straight line when
passed through an electric field? (1 point) *hint remember radiation,
not particles. Beta is misleading
a
.
b
.
c
.
d
.
alp
ha
bet
a
ga
mm
a
prot
on
23.
Molecules in a sample of NH3(l) are held closely together by
intermolecular forces *hint In the NH3 molecule, there is a covalent bond
between N and H. But the N "wants" the electrons more than the H does, so it
pulls them closer to itself. You end up with a little more than half the negative
charge from the bond on the N, and a little less than half on the H. That means N
has a partial negative charge and H has a partial positive charge. These partial
charges are attracted to each other, and that's what holds the molecules close
together.
a
.
b
.
(1 point)
existing between ions
existing between electrons
c
.
d
.
caused by different numbers of
neutrons
caused by unequal charge
distribution
24.
Which sample of matter is a mixture? (1 point) *aq means
dissolved in water, (aqueous)
a
.
b
.
c
.
d
.
H2O(
s)
H2O(
g)
NaCl
(l)
NaCl
(aq)
25.
The concept of an ideal gas is used to explain (1 point) *hint
remember kinetic molecular theory. BEHAVIOR!
a
.
b
.
c
.
d
.
the mass of a gas sample
the behavior of a gas sample
why some gases are
monatomic
why some gases are
diatomic
26.
Which statement concerning elements is true? (1 point) *hint
remember specifics about atom models
a
.
b
.
c
.
Different elements must have different numbers of isotopes.
Different elements must have different numbers of neutrons.
All atoms of a given element must have the same mass
number.
d
.
All atoms of a given element must have the same atomic
number.
27.
Which characteristic is a property of molecular
substances? (1 point) *hint a candle is a molecular substance
a
.
good heat conductivity
b
.
good electrical
conductivity
c
.
low melting point
d
.
high melting point
28.
All chemical reactions have a conservation of (1 point)
*hint mass and charge are very important things
a
.
mass, only
b
.
mass and charge, only
c
.
charge and energy,
only
d
.
mass, charge, and
energy
29.
Which substance represents a compound? (1 point)
*hint simple letters doesn’t signify elements. Co is cobalt. CO is
carbon and oxygen (carbon monoxide)
a
.
b
.
c
.
d
.
C(
s)
C
o(
s)
O2
C
O(
g)
30.
At 298 K, oxygen (O2) and ozone (O3) have different
properties because their (1 point) *hint these guys have different
shapes, shapes changes its characteristics
a
.
atoms have different atomic numbers
b
.
atoms have different atomic masses
c
.
molecules have different molecular structures
d
.
molecules have different average kinetic
energies
31.
Which compound contains only covalent bonds? (1 point)
*hint ionic is nonmetal with metal
a
.
b
.
NaO
H
Ba(
OH)2
c
.
d
.
Ca(
OH)2
CH3
OH
32.
What determines the order of placement of the elements on
the modern Periodic Table? (1 point)
*hint first periodic table was ordered by atomic mass but later
changed to atomic ___
a
.
b
.
c
.
d
.
atomic number
atomic mass
the number of neutrons, only
the number of neutrons and
protons
33.
The atomic mass of an element is the weighted average of
the masses of (1 point) *hint you would want all right?
a
.
b
.
c
.
d
.
its two most abundant isotopes
its two least abundant isotopes
all of its naturally occurring
isotopes
all of its radioactive isotopes
34.
Which statement is true about a proton and an electron? (1
point) *hint electron’s mass 1/1856 of a protons
a
.
b
.
c
.
They have the same masses and the same
charges.
They have the same masses and different
charges.
They have different masses and the same
charges.
d
.
They have different masses and different
charges.
35.
Which of these phrases best describes an atom? (1 point)
*hint modern atomic theory
a
.
b
.
c
.
d
.
a positive nucleus surrounded by a hard negative shell
a positive nucleus surrounded by a cloud of negative
charges
a hard sphere with positive particles uniformly embedded
a hard sphere with negative particles uniformly
embedded
36.
Which nuclide is a radioisotope used in the study of organic
reaction mechanisms? (1 point) *hint what do scientist use to date
old artifacts?
a
.
carbon12
b
.
c
.
d
.
carbon14
uranium235
uranium238
37.
In a fusion reaction, reacting nuclei must collide. Collisions
between two nuclei are difficult to achieve because the nuclei
are (1 point) *hint they tend to repel. Like charges repel
a
.
b
.
c
.
d
.
both negatively charged and repel each
other
both positively charged and repel each
other
oppositely charged and attract each other
oppositely charged and repel each other
38.
Compared to the boiling point of H2S, the boiling point of H2O
is relatively high. Which type of bonding causes this
difference? (1 point) *hydrogen bonding is between Hydrogen and
with either flourine, oxygen, and nitrogen.
a
.
b
.
c
.
d
.
coval
ent
ionic
netw
ork
hydro
gen
39.
The gram atomic mass of oxygen is 16.0 grams per mole.
How many atoms of oxygen does this mass represent? (1 point)
*hint per mole same amount of atoms (Avogadro’s number)
a
.
16.0
b
.
c
.
d
.
32.0
6.02 x
1023
2(6.02 x
1023)
40.
Which element in Group 1 has the greatest tendency to lose
an electron? (1 point) *hint the larger atom, further away from
nucleus. Go down group
a
.
b
.
c
.
d
.
cesiu
m
rubidiu
m
potass
ium
sodiu
m
41.
Which element is classified as a metalloid (semimetal)? (1
point) *hint look at periodic table
a
.
b
.
c
.
d
.
sulfu
r
silic
on
bari
um
bro
min
e
42.
A student calculates the density of an unknown solid. The
mass is 10.04 grams, and the volume is 8.21 cubic centimeters.
How many significant figures should appear in the final
answer? (1 point) *hint use the number with the least amount of
significant digits
a
.
b
.
4
3
c
.
d
.
2
1
43.
Which group contains a liquid that is a nonmetal at STP? (1
point) *hint group 17 contains Br which is a liquid. Iodine is a solid.
Mercury is a liquid (it’s a metal though)
a
.
b
.
c
.
d
.
1
4
1
5
1
6
1
7
44.
How many days are required for 200. gram of radon-222 to
decay to 50.0 grams? (1 point) *hint look at the reference table for
half life times
a
.
b
.
c
.
d
.
11.5
days
7.64
days
3.82
days
1.91
days
45.
When ionic bonds are formed, metallic atoms tend to (1
point) *metals become cations. Loose and get (+)
a
.
b
.
lose electrons and become negative
ions
lose electrons and become positive
ions
c
.
gain electrons and become negative
ions
d
.
gain electrons and become positive
ions
46.
The ability to conduct electricity in the solid state is a
characteristic of metallic bonding. This characteristic is best
explained by the presence of (1 point) *hint we need a moving
electrons something to be conducting. When an ionic solid is dissolved
in water it can conduct also.
a
.
high ionization
energies
b
.
high
electronegativities
c
.
mobile protons
d
.
mobile electrons
47.
Atoms of which element have the weakest attraction for
electrons? (1 point) *hint metals don’t want electrons
a
.
b
.
c
.
d
.
N
a
P
S
S
i
48.
An atom with the electron configuration
2
2
1s 2s 2p63s23p63d54s2 has an incomplete (1 point) *hint d sublevel
in 3rd principal energy level can fill 10 electrons
a
.
b
.
c
.
2p sublevel
second principal energy
level
third principal energy
level
d
.
4s sublevel
49.
What is the pressure of a mixture of CO2, SO2, H2O gases, if
each gas has a partial pressure of 250 torr? (1 point) *Daltons law
of partial pressures. p1 + p2 + p3 + p4 + …. = pt (pressure total)
a
.
b
.
c
.
d
.
250
torr
500
torr
750
torr
1000
torr
50.
The particles of a substance are arranged in a definite
geometric pattern and are constantly vibrating. This substance can
be in (1 point) *hint solids are moving (slightly)
a
.
b
.
c
.
d
.
1)d
2)c
3)d
4)a
5)b
6)d
7)b
8)c
9)d
10)c
11)b
12)d
the solid phase, only
the liquid phase, only
either the liquid or the solid
phase
neither the liquid nor the solid
phase
13) c *
14)c
15)b
16)b
17)c
18)a
19)a
20)d
21)b
22)c
23)d
24)d
25)b
26)d
27)c
28)b
29)d
30)c
31)d
32)a
33)c
34)d
35)b
36)b
37)b
38)d
39)c
40)a
41)b
42)b
43)d
44)b
45)b
46)d
47)a
48)c
49)d
50)a (I think these are the answers)
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