Chemistry CA 2 Practice
Some questions (c) 2015 by Region 10 Educational Service Center.
Some questions (c) 2015 by Progress Testing.
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1 Which of the following is the mass in grams of
5
4.25 × 10³ mol of N2 ?
2
A
2.35 × 10-4 g
B
1.52 × 102 g
C
5.95 × 104 g
D
1.19 × 105 g
A student mixes 36.0 grams of silver nitrate
solution with 30.0 grams of sodium chromate
solution. The mass of the products, which
includes the resulting solution and precipitate,
is equal to 66.0 grams. Which of the following
best explains these results?
Zachary is tasked with carefully measuring
A
law of conservation of mass
B
law of definite proportions
C
law of multiple proportions
D
law of conservation of energy
precisely one mole of aluminum. How should
Zachary go about completing this assignment?
A
He should obtain 27 aluminum pellets.
B
He should obtain 27 grams of aluminum.
C
He should obtain 13 grams of aluminum. 6
LiCl?
D
3
He should obtain 27 atoms of aluminum.
A
chlorine lithide
B
chlorolithium
C
lithium chloride
D
lithium chlorine
A mixture of iron and sulfur can be separated
by attracting the iron particles with a magnet.
7
What is the empirical formula for the
If the iron and sulfur mixture is heated
compound that has 46 grams of sodium, 64
strongly, iron (II) sulfide forms, which is no
grams of sulfur, and 48 grams of oxygen?
longer magnetic and cannot be separated by
A
Na2 S2 O3
B
Na3 S2 O2
C
Na2 S2 O2
D
Na3 S3 O3
physical methods. What is iron (II) sulfide?
A
element
B
compound
C
homogenous mixture
D
heterogeneous mixture
8
4
Which of the following is the scientific name for
Which particles are represented by the dots in
Which of the following is a balanced chemical
equation describing the formation of water?
Lewis dot diagram?
A
H2 + O2 ↔ H2 O
A
core electrons
B
H2 + 2O2 ↔ H2 O
B
valence electrons
C
2H2 + O2 ↔ 2H2 O
C
protons
D
2H2 + 2O2 ↔ 2H2 O
D
all electrons
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9
Which of the following is the correct Lewis dot
12
How many molecules are in 2.50 moles of
diagram?
H2 O?
A
A
1.51 X 102 4 molecules of H2 O
B
4.15 X 10-24 molecules of H2 O
C
3.01 X 102 4 molecules of H2 O
D
8.31 X 10-24 molecules of H2 O
B
C
13
D
Vinegar, a common household item, is used in
cleaning, cooking, baking and meat
preservation. Vinegar contains acetic acid,
CH3 COOH, which gives vinegar its sour taste
10
What is the empirical formula of a compound
and pungent smell. What is the percent
that has 40% carbon, 6.7% hydrogen, and
composition of carbon in acetic acid?
53.3% oxygen?
A
CH2 O
B
C2 HO
C
C2 H2 O2
D
CHO2
14
11
A
40.0%
B
41.4%
C
20.0%
D
33.3%
A compound is found to have an empirical
What is the molecular formula of a compound
formula of CH2 O. What is the molecular
that has a molecular weight of 240.0 grams?.
formula when the molecular weight is 180.0
A 5.00-gram sample contains 2.00 grams of
grams?
carbon, 0.34 grams of hydrogen, and 2.69
A
C2 H4 O2
B
C6 H8O6
C
C6 H1 2O6
D
C1 2H2 4O1 2
grams of oxygen.
A
C6 H1 2O6
B
C8H1 6O8
C
C1 6H3 2O1 6
D
C5 H1 0O5
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15
16
Which of the following is a single replacement reaction?
A
CaCO3 (s) ↔ CaO(s) + CO2 (g)
B
4Al(s) + 3O2 (g) ↔ 2Al2 O3 (s)
C
Mg(s) + 2HCl(a q) ↔ H2 (g) +MgCl2 (a q)
D
2C4 H1 0(g) + 13O2 (g) ↔ 8CO2 (g) + 10H2 O(g)
The unbalanced equation below represents the reaction of solid aluminum hydroxide with hydrochloric
acid.
Al(OH)3 + HCl --> AlCl3 + H2 O
Which of the following represents the correct, balanced chemical equation for the above reaction?
17
A
Al(OH)3 + HCl3 --> AlCl3 + 2 H2 O
B
Al(OH)3 + HCl3 --> AlCl3 + 4 H2 O
C
Al(OH)3 + 3 HCl --> AlCl3 + 3 H2 O
D
Al(OH)3 + 3 HCl --> AlCl3 + 6 H2 O
During the combustion of methane (CH4 ), one mole of methane gas combines with two moles of oxygen
gas (O2 ) to produce one mole of carbon dioxide gas (CO2 ) and two moles of water vapor. Which of the
following chemical equations correctly represents the combustion of methane described above?
18
A
CH4 (g) + 2O(g) ↔ CO(g) + 2H2 O(l)
B
CH4 (g) + 2O2 (g) ↔ CO(g) + 2H2 O(l)
C
CH4 (g) + 2O2 (g) ↔ CO2 (g) + 2H2 O(g)
D
CH4 (g) + 2O(g) ↔ CO2 (g) + 2H2 O(g)
What is the molar mass of KBr?
19
How many moles are there in 8.50 X 102 4
A
54.0 g/mol
molecules of sodium sulfate?
B
74.1 g/mol
A
1.40 moles
C
119 g/mol
B
14.1 moles
D
1.20 X 102 4 g/mol
C
51.2 moles
D
5.12 X 1048 moles
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20
21
Which of the following has the highest mass?
A
50.0 g water
B
50.0 mol NaCl
C
50.0 molecules carbon dioxide
D
50.0 mg of oxygen gas
24
The following picture shows a covalent
molecule.
What mass of sulfur would have precisely 4.7
x 102 2 atoms of sulfur?
22
23
A
6.02 g sulfur
What molecule listed below has the same
B
4.7 g sulfur
shape?
C
2.5 g sulfur
A
BH3
D
1.3 g sulfur
B
H2 O2
C
NH3
D
Na3 P
What is the molar mass of CO2 ?
A
22.0 g/mol
B
28.0 g/mol
C
44.0 g/mol
D
56.0 g/mol
25
Which of the following molecules has a
What is the molar mass of carbon?
A
6.0 g/mol
B
12.0 g/mol
C
22.4 g/mol
D
6.02 X 102 3 g/mol
central atom with precisely two unshared
pairs of electrons?
A
ammonia, NH3
B
methane, CH4
C
water, H2 O
D
hydrocyanic acid, HCN
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26
Which of the following compounds would
NOT be expected to exhibit a linear
molecular geometry?
A
carbon dioxide, CO2
B
beryllium fluoride, BeF2
C
hydrogen sulfide, H2 S
D
hydrocyanic acid, HCN
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27
A student carefully measures a certain quantity of four different substances into trays that will be used
in a laboratory exercise. Which of these trays would contain the largest number of atoms?
sample
mass of empty tray
mass of tray with sample
water
37.86 g
55.88 g
table salt (NaCl)
36.59 g
95.03 g
copper wire
37.41 g
100.96 g
lead shot
38.08 g
245.20 g
28
A
water
B
table salt
C
copper wire
D
lead shot
What is a mole in chemistry terms?
A
a mammal found in Eurasia and North America
B
an SI unit for measuring the amount of a substance
C
a benign tumor sometimes found on human skin appearing as a small, sometimes raised area of skin,
usually with darker pigment
D
29
30
a Mexican sauce made from chili peppers, other spices, and chocolate
What is the molecular shape of a CCl4
31
Which of the following molecules would be
molecule?
expected to exhibit a tetrahedral geometry?
A
bent
A
NH3
B
linear
B
CH2 O
C
tetrahedral
C
H2 O
D
trigonal planar
D
CH4
Around the central atom in a covalently
bonded molecule, there are four pairs of
electrons: three shared pairs and one
unshared pair. The geometry of this
32
Which of the following molecules would be
expected to exhibit a trigonal planar
geometry?
molecule is best described as — A
NH3
A
linear
B
CH2 O
B
trigonal planar
C
H2 O
C
trigonal pyramidal
D
CH4
D
tetrahedral
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33
34
What is the shape of a CO2 molecule?
A
linear
B
tetrahedral
C
D
38
Which of the following is the metallic ion in
sodium fluoride?
A
Na 1 -
trigonal planar
B
Na 1 +
bent
C
F 2-
D
F 2 +
Which of the following is the correct formula
for mercury(II) chloride?
A
HgCl
B
HgCl2
C
Hg2 Cl
D
Hg2 Cl2
39
Which of the following best describes the
arrangement of electrons in a metallic bond?
A
Electrons are transferred from one atom
to another.
B
Electrons exist as shared electron pairs
between neutral atoms.
35
36
37
C
What is the formula for copper (I) oxide?
A
Cu2 O3
B
Cu2 O
C
CuO2
D
CuO
Electrons are delocalized in a "sea of
electrons" and are shared among the
positively charged metal ions.
D
Electrons are shared unequally, creating
a bond with partial positive and negative
poles.
What is the formula for sodium fluoride?
A
NaF
B
Na2 F
chloride, KCl?
C
NaF2
A
32.3 amu
D
Na2 F2
B
74.6 amu
C
149.2 amu
D
154.5 amu
What is the formula for iron (II) oxide?
A
Fe2 O2
B
Fe2 O
C
FeO
D
FeO2
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40
What is the formula mass of potassium
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41
42
43
How many hydrogen atoms are there in 7.30
44
The percent by mass of oxygen in Na2 SO4
moles of ethanol (C2 H5 OH)?
(gram formula mass = 142 grams) is closest
A
1.21 X 10-23 atoms
to which of the following?
B
2.20 X 102 5 atoms
C
2.64 X 102 5 atoms
D
4.39 X 102 4 atoms
What is the mass percent of carbon in
45
A
64%
B
45%
C
11%
D
22%
What is the percent by mass of sulfur in sulfur
glucose, C6 H1 2O6 ?
dioxide?
A
25.00% C
A
32%
B
40.00% C
B
33%
C
41.40% C
C
67%
D
72.07% C
D
50%
What is the approximate percent by mass of
aluminum in Al2 O3 ?
A
18.9%
B
47.1%
C
52.9%
D
35.4%
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46
What is the approximate percent
composition by mass of CaBr2 (gram formula
mass = 200 grams)?
A
35% calcium and 65% bromine
B
25% calcium and 75% bromine
C
30% calcium and 70% bromine
D
20% calcium and 80% bromine
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47
What is the percent by mass of oxygen in
51
Fe2 O3 (gram formula mass = 160 grams)?
A
56%
B
30%
C
70%
D
16%
The percent by mass of oxygen in H2 C2 O4 is
equal to which of the following expressions?
A
× 100
B
× 100
48
C
What is the approximate percent by mass of
× 100
oxygen in SO3 ?
49
A
60%
B
40%
C
20%
D
80%
What is the approximate percent by mass of
potassium in KHCO3 ?
A
39%
B
24%
C
19%
D
61%
D
× 100
52
One step in the production of copper is to
heat copper (I) sulfide, Cu2 S, with oxygen.
This produces copper (I) oxide and sulfur
dioxide gas according to the following
reaction:
2 Cu2 S(s) + 3 O2(g) -> 2 Cu2 O(s) + 2 SO2(g)
Which is the greatest mass of SO2 that can be
produced from 15.0 mol Cu2 S?
50
What is the percent by mass of hydrogen in
NH3 (gram formula mass = 17.0 grams)?
A
17.6%
B
82.4%
C
21.4%
D
5.9%
Page 10
A
4.80 × 10² g SO2
B
7.21 × 10² g SO2
C
9.61 × 10² g SO2
D
1.92 × 10³ g SO2
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53
The percent by mass of nitrogen in Mg(CN)2
55
Aqueous lead nitrate is combined with
aqueous potassium chromate to form solid
is equal to which of the following?
lead chromate and potassium nitrate in
A
solution. If 25.0 grams of each reactant is
used, what is the percent yield of lead
× 100
chromate if 20.0 grams of PbCrO4 is
collected?
B
K2 CrO4 + Pb(NO3 )2 à PbCrO4 + 2KNO3
× 100
C
× 100
A
58.8 %
B
66.6 %
C
69.0 %
D
81.5 %
D
× 100
56
The reaction between solid sodium and iron
(III) oxide is one of a series of reactions that
inflate an automobile airbag.
6 Na(s) + Fe2 O3 (s) à 3 Na2 O (s) + 2 Fe (s)
54
A student burns 1.50 mol C3 H8 according to
If 25.0 grams of each reactant is used, what is
the limiting reactant?
the following reaction:
A
Na
How many grams of carbon dioxide are
B
Fe2 O3
produced?
C
Na2 O
D
Fe
C3 H8 + 5O2 A
4.40 × 10¹ g
B
6.61 × 10¹ g
C
1.32 × 10² g
D
1.98 × 10² g
Page 11
3CO2 + 4H2 O.
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