Exam 1 Practice Review-3.docx
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Feb 20, 2024
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Chemistry 1040
Practice Exam Question List
CH 1-3
1. The result of (10.8325
x
3.252) + 4.4 is properly written with correct sig figs as
A) 40
B) 40.
C) 39.6
D) 39.63
E) 39.627
2. Which of the following results in shooting at a target (each of five shots marked by an x)
is a good example of
systematic error
?
3. When the little one was teething, he shed 150.0 milligrams of tears per minute (all day,
every day). What is this in kg tears/year (assuming 365 days = 1 year)?
A)
1.500 x 10
-4
kg tears/year
D)
78.84 kg tears/year
B)
285.4 kg tears/year
E)
5.256 x 10
5
kg tears/year
C)
1.235 kg tears/year
4. Caffeine, C
8
H
10
N
4
O
2
(molar mass = 194 g/mole), is super cool! How many molecules of
caffeine are in 500. milligrams of caffeine?
A) 1.55 x 10
21
molecules
B) 1.61 x 10
-16
molecules
C) 9.70 x 10
7
molecules
D) 1.55 x 10
24
molecules
E) 3.67 x 10
23
molecules
5. What are the coefficients when the following reaction is balanced?
____ FeCl
3
+
____ NaOH
→
____ Fe(OH)
3
+
____ NaCl
A)
1,1,1,1
B)
3,3,3,3
C)
1,3,1,3
D)
3,1,3,1
E)
4,3,2,5
6. Using the balanced reaction below, how many grams of KBr (119g/mole) would you
make by reacting 8.75g of AlBr
3
(267g/mole) with excess K
2
SO
4
?
2 AlBr
3
+
3 K
2
SO
4
±
Al
2
(SO
4
)
3
+
6 KBr
A) 3.9g
B) 0.0983g
C) 11.7g
D) 2.75x10
-4
g
E) 2.78x10
5
g
7. When applying the scientific method, the ______ is the tentative proposal that explains observations.
A) model (theory)
B. experiment
C. natural law
D. hypothesis
8. How many scruples are there in 25.80 lb? Here are some potentially useful things:
1.000 scruples = 20.00 grains
1.000 gram = 15.40 grains
1.000grain = 0.06480 grams
1.000 lb = 453.60grams
1.000 kg = 2.205 lb
A)
0.01990 scruples
B)
9.028 scruples
C)
583.9 scruples
D)
2.35 x 10
5
scruples
E)
9011 scruples
9. What is the ratio of atoms of hydrogen to atoms of sulfur, H:S, in (NH
4
)
2
SO
4
?
A) 2:1
B) 8:1
C) 6.4:1
D) 1:4
E) 2:8
10. What is the empirical formula of a compound that is 54.5% C; 9.2% H; and 36.3% O by mass?
A) C
6
H
4
O B) C
4
H
8
O
2
C) C
2
H
4
O
D) C
3
H
4
O
E) C
3
H
4
O
3
11. What is the molecular formula of a compound that has a molar mass of 30.07 g/mole and an empirical
formula of CH
3
?
A) CH
B) CH
3
C) C
2
H
6
D) C
3
H
9
E)C
2
H
3
12.
Carbon dioxide, CO
2
(molar mass = 44.0 g/mole), is everywhere. How many molecules
of CO
2
do you have in 2.48 kilograms of CO
2
?
A) 1.49 x 10
24
molecules
B) 5.64 x 10
-2
molecules
C) 6.57 x 10
25
molecules
D) 3.39 x 10
25
molecules
E) 1.09 x 10
2
molecules
13. The formula weight of Al
2
(SO
4
)
3
is
A) 123 g/mole
B) 278 g/mole
C) 308 g/mole
D) 342 g/mole
E) 371 g/mole
14. What are the coefficients when the following reaction is balanced?
____ CaO
+
____ P
4
O
10
→
____ Ca
3
(PO
4
)
2
A)
1,1,1
B)
1,1,4
C)
3,1,2
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D)
6,2,2
E)
6,1,2
15. How many oxygen (O) atoms can be found in 2.74 grams of Al
2
(SO
4
)
3
(molar mass = 342 g/mole)?
A) 12
B) 6.02 x 10
23
C) 7.22 x 10
24
D) 5.79 x 10
22
E) 8.01 10
-3
16. According to the following balanced equation, how many moles of H
2
O are formed when 43.8 grams of
NH
3
are treated with an excess of O
2
?
4 NH
3
+
7 O
2
±
4 NO
2
+
6 H
2
O
A) 2.58 moles
B) 3.86 moles
C) 15.5 moles
D) 0.644 moles
E) 0.429 moles
17. Consider the following balanced equation: CS
2
+
3 O
2
±
2 SO
2
+
CO
2
(g)
You reacted 3.22 moles of CS
2
with excess O
2
and actually made 345g of SO
2
(molar mass = 64 g/mole)
What is the % yield of this reaction?
A) 1.56%
B) 25.0%
C) 34.5%
D) 83.7%
E) 97.2%
21. An experiment calls for 10.0 mLs of bromine (density = 3.12 g/mL). Since an accurate balance is available,
it is decided to measure bromine by mass. How many grams should be measured out?
(a) 31.2
(b) 3.21
(c) 0.312
(d) 3.12
(e) 32.1
22. An experiment calls for 10.0 grams of bromine (density = 3.12 g/mL). Since an accurate graduated cylinder
is available, it is decided to measure bromine by volume. How many mL should be measured out?
(a) 31.2
(b) 3.21
(c) 0.312
(d) 3.12
(e) 32.1
23. An experiment needs 10.0 meters of rope (rope has 3.12 knots/meter). How many knots will your
experimental rope have?
(a) 31.2
(b) 3.21
(c) 0.312
(d) 3.12
(e) 32.1
24. Chopping a block of wood in half is a _________ change and freezing liquid ethanol into solid ethanol is a
________ change.
A. physical, physical
B. physical, chemical
C. chemical, chemical
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D. chemical, physical
25. Shaping copper into the shape of a statue is a _________ change and putting copper into an acid and
forming a gas is a _________ change.
A. physical, physical
B. chemical, chemical
C. physical, chemical
D. chemical, physical
26. The pressure of a gas increases as the volume of the container decreases. In the scientific method, this is an
example of a/an ______.
A) theory
B) hypothesis
C) experiment
D) natural law
27. Clem the chemist loves his truck but it only can travel 19.2 miles per gallon. Before upgrading his truck he
wanted to see if he could convert its gas mileage into units of kilometers (km) per centiliter (cL).
Given that 1.00 gallon = 3.79 liters and 1.00 mile = 1609 meters, what did he calculate?
A) 815 km/cL
B) 11700 km/cL
C) 0.0815 km/cL
D) 0.452 km/cL
E) 1.92x10
-4
km/cL
28. You ordered a package online and noticed on the website that it was being shipped in a box that had a
volume of 3.75 m
3
. What is the volume of the box in ft
3
? (2.54 cm = 1.00 in.; 12.0 in. = 1.00 ft)
A) 1.35 ft
3
B) 173 ft
3
C) 114 ft
3
D) 132 ft
3
E) 1.23x10
-3
ft
3
29. Dr. Boating was cruising the open ocean in her beautiful new yacht. She was traveling at 41.2 knots. How
fast was she going in meters per minute (m/min)?
1.00 knot = 1.852 kilometers per hour (km/hr))
A) 1270 m/min
B) 4.58 m/min
C) 309 m/min
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D) 1.27x10
-3
m/min
E) 3.09x10
-5
m/min
30. What is the molar mass of C
4
H
6
O
3
?
A) 29 g/mole
B) 102 g/mole
C) 13 g/mole
D) 64 g/mole
31. How many molecules of Na
3
PO
4
are in 3.75 moles of Na
3
(PO
4
)
3
?
A) 3.75 molecules Na
3
PO
4
B) 6.23x10
-24
molecules Na
3
PO
4
C) 6.78x10
24
molecules Na
3
PO
4
D) 4.07x10
23
molecules Na
3
PO
4
E) 2.26x10
24
molecules Na
3
PO
4
32. How many atoms of C are in 2.35 grams of C
2
H
4
O
2
? (molar mass of C
2
H
4
O
2
= 60.1 g/mole)
A) 2.35x10
22
atoms of C
B) 1.70x10
26
atoms of C
C) 7.82x10
-2
atoms of C
D) 4.71x10
22
atoms of C
E) 0.588 atoms of C
33. How many grams of Cl are in 8.75x10
25
molecules of FeCl
3
? (molar mass of Cl = 35.45 g/mole)
A) 145 g Cl
B) 5.15x10
3
g Cl
C) 1.55x10
4
g Cl
D) 435 g Cl
E) 3.10x10
27
g Cl
34. How many moles of KNO
3
are in 545.6 grams of KNO
3
? (molar mass of KNO
3
= 162.2 g/mole)
A) 3.364 moles KNO
3
B) 8.85x10
4
moles KNO
3
C) 16.82 moles KNO
3
D) 10.09 moles KNO
3
E) 1.12 moles KNO
3
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35. An interesting compound that can turn your hands colors is made up of 63.5% Ag, 8.2% N, and 28.3% O.
What is the compound’s empirical formula? (Ag = 107.87 g/mole; N = 14.01 g/mole; O = 16 g/mole)
A) AgNO
B) AgNO
3
C) Ag
16
NO
7
D) AgNO
2
E) Ag
0.5
N
0.5
O
1.75
36. Consider a substance with the empirical formula of C
2
H
3
O. What is the molecular formula of this substance
if the molar mass is approximately 215 g/mole?
(C = 12.01 g/mole; H = 1.01 g/mole; O = 16.00 g/mole)
A) C
12
HO
16
B) C
10
H
15
O
5
C) C
2
H
3
O
D) C
4
H
6
O
2
E) C
8
H
12
O
4
37. Balance the following equation. When balanced, what is the coefficient in front of O
2
?
____ C
2
H
4
+ ____ O
2
→
____ CO
2
+ ____ H
2
O
A) 6
B) 1
C) 2
D) 3
E) 4
38. Balance the following equation. When balanced, what is the coefficient in front of KNO
3
?
____ Mg(NO
3
)
2
+ ____ K
3
PO
4
→
____ Mg
3
(PO
4
)
2
+ ____ KNO
3
A) 3
B) 6
C) 8
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D) 2
E) 1
39. Consider the following balanced chemical equation: C
3
H
8
+ 5 O
2
±
4 H
2
O + 3 CO
2
How many moles of H
2
O can be produced from 12.5 moles of O
2
(assume you have excess C
3
H
8
)?
A) 10.0 moles H
2
O
B) 50.0 moles H
2
O
C) 2.50 moles H
2
O
D) 20 moles H
2
O
E) 180. moles H
2
O
40. Consider the following balanced equation: 2 Na + I
2
±
2 NaI
How many grams of I
2
are needed to make 845.6 grams of NaI (assume excess Na)?
(Na = 22.99 g/mole; I
2
= 253.8 g/mole; NaI = 149.9 g/mole)
A) 2863 g I
2
B) 1432 g I
2
C) 4668 g I
2
D) 64.84 g I
2
E) 715.9 g I
2
41.Consider the following balanced equation: 2 NaBrO
3
±
2 NaBr + 3 O
2
How many grams of O
2
would be made from 435.7 grams of NaBrO
3
?
(NaBrO
3
= 150.9 g/mole; O
2
= 32.00 g/mole; NaBr = 102.9 g/mole)
A) 92.39 g O
2
B) 277.2 g O
2
C) 138.6 g O
2
D) 61.59 g O
2
E) 653.6 g O
2
42. In a chemical reaction Carla the chemist set up a chemical reaction in the lab to make caffeine. She
calculated that she could theoretically make 25.45 grams of caffeine. In the lab she actually ended up making
18.32 grams of caffeine. What was her % yield?
A) 71.98 %
B) 1.389 %
C) 28.02 %
D) 7.13 %
E) 43.77 %
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43. Consider the following balanced chemical equation: N
2
+ 3 H
2
±
2 NH
3
If 28 grams of N
2
(28 g/mole) is reacted with 25 grams of H
2
(2.02 g/mole), which would be the limiting
reactant?
A) H
2
B) N
2
C) NH
3
D) There is no limiting reactant
44. Which of the following is true of an element? A) An element is a substance composed of atoms of two or more elements
B) An element is a substance that cannot be separated into simpler substances by chemical means.
C) An element is combination of two or more substances in which the substances retain their distinct identities.
D) An element must be heterogeneous
E) An element must be a solid at room temperature
45. Calculate the average atomic mass of the element (Fake – Fa) using the following data:
Isotope% abundance
mass
6
Fa
7.5%
6.0151 amu
7
Fa
92.5%
7.0160 amu
A) 6.51 amu
B) 6.02 amu
C) 6.94 amu
D) 7.02 amu
E) 13.0 amu
46. An atom of the isotope
Ba consists of how many protons (p), neutrons (n), and electrons (e)? 137 56 A) 56 p, 137 n, 56 e
B) 56 p, 81 n, 56 e
C) 137 p, 81 n, 56 e
D) 56 p, 56 n, 56 e
E) 81 p, 56 n, 81 e
47. An aluminum ion, Al
3+
, has: A) 13 protons and 13 electrons
B) 27 protons and 24 electrons
C) 16 protons and 13 electrons
D) 13 protons and 10 electrons
E) 10 protons and 13 electrons
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Page
52. All atoms of the same type of element have the same number of __________________.
A) isotopes B) allotropes C) neutrons D) reactions E) protons
53. When applying the scientific method, the ______ is the tentative proposal that explains observations. A)
model (theory) B. experiment C. natural law D. hypothesis
54. Super-Secret Compound X has three naturally occurring isotopes:
Isotope Isotopic Mass (amu) Abundance (%)
17
X
16.97
25.2
18
X
18.05
62.5
19
X
18.95
12.3
What is the average atomic mass of Super-Secret Compound X?
A) 18.3 amu B) 17.9 amu C) 16.2 amu D) 33.3 amu E) 11.3 amu
56. Which of the following ions occurs commonly?
A) Mg
2+
B) O
2+
C) K
2+
D) F
2-
E) Cl
+
57. What is the name of MnS?
A) Manganese monosulfide
B) Manganese (III) sulfide
C) Manganese (I) sulfide
D) Manganic sulfide
E) Manganese (II) sulfide
58. What is the formula for ammonium sulfate?
A) AmS D) NH
4
(SO
4
)
2
B) (NH
4
)
2
S E) AmSO
4
C) (NH
4
)
2
SO
4
59. What is the name of SeF
6
?
A) Selenium fluoride
B) Selenium (VI) fluoride
C) Hydroselenic acid
D) Selenium flourous acid
E) Selenium hexafluoride
60. Which of the following compounds is covalent?
A) SO
3
B) MgO C) Na
2
O D) Au
2
O
3
E) FeBr
2
61. What is the formula for the compound formed when sodium (Na) and nitrogen (N) come together?
A) NaN B) NaN
2
C) Na
2
N D) Na
3
N E) NaN
3
62. How many neutrons does
14
C have?
A) 6 B) 8 C) 12 D) 14 E) 20
63. How many protons does Manganese (Mn) have?
A) 25 B) 30 C) 55 D) 80 E) 7
64. The alkaline earth metal (group 2A) in the 5th period of the periodic table is ___?___.
A) Rb B) Sr C) I D) At E) Ca
Even more practice
1. Label the following as either a physical or chemical change?
a) Freezing Water _________________
b) Activating Glow-Sticks _________________
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2. Bud N. Chemist must determine the density of a mineral sample. His four trials yield densities of:
Trial 1: 5.89 g/cm
3
WORD BANK
Trial 2: 5.88 g/cm
3
HIGH, LOW, PRECISION, ACCURACY
Trial 3: 5.90 g/cm
3
RANDOM, SYSTEMATIC
Trial 4: 5.89 g/cm
3
If an independent expert found the correct density to be 4.75 g/cm
3
, please fill in the blanks (5 spots to fill in!)
using the word bank above – you may use a word more than once and not all words will be used.
Bud’s results show __________
________________ AND __________ _________________.
His measurements must have had _________________ error.
3. Convert 3.4x10
3
g/mm to units of kg/m. (mm means millimeters and kg means kilograms)
4.
Briefly
explain the relationship between hypothesis and experiment in the scientific method.
5. How many significant figures do the following numbers contain?
a) 970.0
b) 502
c) 0.300
d) 0.0043
e) 20.01
_______
________
_________
________
_______
6. Given that 1 inch = 2.54 cm. Convert 2.13 m
3
into in
3
.
7.
Briefly
explain how a theory is different than a fact.
8. How many significant figures do the following numbers contain?
a) 420
b) 18.25
c) 12.030
d) 0.014
e) 4.01005
_______
________
_________
________
_______
9. Given that 454 grams = 1.00 lb Convert 2.35x10
4
cg (cg means centigrams) into lbs.
10. Convert 5.65 seeds/ft
2
to units of plants/meter
2
.
12.0 seeds = 1 plant
1.00 ft = 12.0 in.
9 |
Page
2.54 cm = 1.00 in
11. Clum Z. Chemist must determine the weight of a chemical sample. Clum’s four trials yield weights of:
Trial 1: 5.89 g
WORD BANK
Trial 2: 7.25 g
HIGH, LOW, PRECISION, ACCURACY
Trial 3: 2.56 g
RANDOM, SYSTEMATIC
Trial 4: 4.54 g
If an independent expert found the correct weight to be 4.75 g, please fill in the blanks (5 spots to fill in!) using
the word bank above – you may use a word more than once and not all words will be used.
Clum’s results show __________
________________ AND __________ _________________.
His measurements must have had _________________ error.
12. Label the following as either a physical or chemical change?
a) Rusting bike in the rain _________________
b) Melting Candle _________________
14. Using the balanced reaction below, how much excess reactant do you have if 17.2g Pb(OH)
2
(241.2
g/mole)reacts with 0.0699 mole HCl?
Pb(OH)
2
+
2 HCl
±
2 H
2
O
+
PbCl
2
10 |
Page
13.
In the combustion of an unknown compound (made of only C, H, and O), you
find that it contains 11.25g C, 1.563g H, and 5.00g O.
A. What is the empirical formula?
B. If its molar mass is between 170 and 180 g/mol, what is its molecular
formula?
Answer in two parts:
A) What is the limiting reactant?
A. How much of the excess reactant do you have left over after the reaction is complete?
15. Fill in the blanks:
a.
How many significant figures does each of the following have?
I.
0.00563 ___________
II.
45.00
___________
b.
What is the answer to the following with the correct number of significant figures:
I.
(45.3 x 22.708) / 25 = _______
II.
8.25 + 4.04 + 3.836 = _______
16. Consider the following chemical equation: 4 CuO + CH
4
±
2 H
2
O + 4 Cu + CO
2
A) What is the limiting reactant
AND
what is the theoretical yield of Cu in grams (molar mass =
63.55g/mole) if 30.0 grams of CuO (molar mass = 79. 5g/mole) and 20.0 grams of CH
4
(16.0 g/mole) are
reacted?
Show work:
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17. Consider the same circumstances as question #16. How many grams of
excess reactant
do you have?
Show work:
18.
Briefly
explain how natural law is different than a theory.
19. How many significant figures do the following numbers contain?
a) 42.0
b) 08.36
c) 5.200
d) 0.0044
e) 1800
_______
________
_________
________
_______
20. Cooper Hooper’s vertical is 23.2 inches. Given that 2.54 centimeters = 1.00 inch. What is this vertical in
millimeters (mm)?
21. Farmer C. H. Emist grows 4250 tomato plants/acre. What is this plant density in tomato/cm
2
?
26.0 tomatoes = 1 tomato plant
1.00 acre = 6.27x10
6
in
2
2.54 cm = 1.00 in
22. Met Iculus was asked to measure the height of a barn. Met’s four trials yield heights of:
Trial 1: 8.72 m
WORD BANK
Trial 2: 8.70 m
HIGH, LOW, PRECISION, ACCURACY
Trial 3: 8.73 m
RANDOM, SYSTEMATIC
Trial 4: 8.71 m
If an independent expert found the correct weight to be 10.2 meters (m), please fill in the blanks (5 spots to fill
in!) using the word bank above – you may use a word more than once and not all words will be used.
12 |
Page
Met’s results show __________
________________ AND __________ _____________
22. Significant Figures
A) Indicate the number of significant figures to the right of the following measurements:
0.0034050 mL. _____
250 mL _____
100.49 mL ______
3007 mL ______
B) What is the answer to the following mathematical calculations expressed in the correct number
of significant figures:
i.
(3.25 x 0.078) ÷ 8.0368 = _______________
ii.
3.25 - 0.078 + 8.0368 = ________________
23. Accuracy, Precision and Error
A) Sid the Science Kid was practicing throwing darts at a target. He threw 5 times. His goal was
to get all of the darts to hit in the center. Draw his five throws (marking where they hit with an
“x”) that show that he had
systematic error
in his throws?
24. A compound is made up of 5.9265% H and 94.0735% O. We also happen to know that the
molar mass of this compound is 34.01468 g/mole. First calculate the
empirical formula
of this
compound and
then calculate the molecular formula
of this compound.
(H = 1.01 g/mole; O = 16.00 g/mole)
Empirical Formula: _____________
13 |
Page
Molecular Formula: _____________
25. (4 pts) Consider the following balanced equation: 4 FeCl
3
+ 3 O
2
± 2 Fe
2
O
3
+ 6 Cl
2
Molar masses: FeCl
3
= 162.2 g/mole; O
2
= 32.00 g/mole; Cl
2
= 70.9 g/mole
You reacted 648.8 grams of FeCl
3
with 128.0 grams of O
2
.
A) What is the limiting reagent (reactant)?
B) What is the theoretical yield of Cl
2
?
C) How much
excess
reagent (reactant) do you have left?
26. Change the chemical formulas to names and names to formulas.
a) iron(II) phosphate ________________
b) dichlorine pentoxide _______________
c) magnesium sulfate _______________
d) NO
2
_______________
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e) NH
4
NO
3 ________________________________
f) Ba(OH)
2
___________________
28. Naming (convert from name to formula or formula to name). Also CIRCLE whether it is an ionic or covalent
compound.
a. Fe(NO
3
)
3
Name:
Ionic or Covalent?
b. Phosphorus pentachloride Formula:
Ionic or Covalent?
c. Ammonium sulfide Formula:
Ionic or Covalent?
29. Consider the nitrogen-15 ion,
15
N
3-
# protons: ______ # neutrons: __________ mass number: __________electrons: _______
30. Iodine has three isotopes. The abundance of
127
I is 80.00%,
126
I is 17.00%, and
128
I is 3.00%. What is the average
atomic mass of iodine?
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DELL
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