Download Exam 1 Review - Clark College

Clark College
Chemistry 131
Exam 1 Review
The answers to this sample exam are on the last page of this handout. Please note that the exam will
be a combination of multiple choice and problem solving. For practice solving problems, please refer to
the lecture notes, suggested problems and homework assignments.
-2
1. The number of significant figures in 8.5001 x 10 is
a. 3.
b. 4.
c. 5.
2.
d.
e.
6.
7.
How many significant figures are there in the value 4,750,330?
a. 7
d.
b. 6
e.
c. 5
4
3
-12
3.
The distance between atoms is sometimes given in picometers, where 1 pm is equivalent to 1 x 10
-8
If the distance between the carbon atoms in diamond is 1.54 x 10 cm, what is this distance in
picometers?
a. 0.154
d. 1,540
b. 1.54
e. 154,000
c. 154
4.
The volume of a 10.0% glucose solution is 8.25 mL. Its density is 1.039 g/mL. What mass does the
solution have?
a. 8.25 g
d. 0.00825 kg
b. 8.57 g
e. 825 mg
c. 0.0857 kg
5.
What is the best answer to report for
a.
b.
c.
6.
3.478 x 1.164
2.00
m.
+ 0.354?
2.3782
2.378
2.38
d.
e.
2.4
2
Which of the following have the correct number of significant figures and units for the mathematical
operation
5
5.25 x 10 ergs x
a.
b.
c.
-5
1.255 x 10 J/cal
-5
1.255 x 10 kcal
-5
1.25 x 10 kcal
1.000 J
7
1.000 x 10 ergs
x
1.000 cal
4.184 J
x
1 kcal
1000 cal
?
d.
e.
-5
1.3 x 10 kcal
-5
1 x 10 kcal
7.
Liquid propane boils at –42°C. What is its boiling point on the Kelvin scale?
a. 231 K
d. 315 K
b. 256 K
e. 345 K
c. 273 K
8.
The melting point and the normal boiling point of water can be used to calibrate thermometers. What are
these respective temperatures in Kelvin degrees?
a. 32 and 212
d. 0 and 373
b. 0 and 100
e. 273 and 373
c. 100 and 273
Exam 1 Review
Distributed on Monday, October 7, 2002
Page 1 of 5
Clark College
9.
Chemistry 131
How many scruples are there in 25.8 lb? Which of the following represents a correct setup to solve the
problem? Some equivalents that may be helpful are given below:
1.00 scruple = 20.0 grains
1.00 g = 15.4 grains
1.00 grain = 0.0648 g
1.00 lb = 453.6 g
1.00 kg = 2.205 lb
a.
b.
c.
d.
e.
1.00 scruple
20.0 grains
20.0 grains
1.00 scruple
1.00 scruple
20.0 grains
1.00 scruple
20.0 grains
1.00 scruple
20.0 grains
x
x
x
x
x
1.00 grain
0.0648 g
x
1.00 g
15.4 grains
15.4 grains
1.00 g
1.54 grains
1.00 g
1.00 grain
0.0648 g
x
x
x
x
1.00 kg
2.205 lb
x
1.00 grain
0.0648 g
0.0648 g
1.00 grain
453.6 g
1.00 lb
1.00 kg
2.205 lb
1.00 lb
453.6 g
x
x
1000 g
x
1 kg
453.6 g
1.00 lb
453.6 g
x 25.8 lb
x 25.8 lb
x 25.8 lb
1.00 lb
x 25.8 lb
x 25.8 lb
3
3
10.
What is the mass of NH3 in a 50.0-cm sample that has a density of 0.90 g/cm and which consists of
28% NH3?
a. 13 g
d. 32 g
b. 15 g
e. 45 g
c. 25 g
11.
Calculate the mass of magnesium that occupies the same volume as 75.0 g of copper. The density of Cu
3
3
= 8.96 g/cm and Mg = 1.74 g/cm .
a. 14.56 g
d. 386 g
b. 14.6 g
e. 386.2 g
c. 15 g
12.
Which of the following is an example of a chemical change?
a. water boiling
d.
b. ice melting
e.
c. alcohol evaporating
13.
How many neutrons are there in the chloride ion,
a.
b.
c.
14.
17
18
20
37
17
iodine vaporizing
a sunburn
-
Cl ?
d. 21
e. 38
3+
How many protons, neutrons, and electrons are in the antimony(III) ion, 123
51 Sb ?
a. 123p, 72n, 123e
d. 72p, 51n, 69e
b. 51p, 72n, 48e
e. 48p, 72n, 51e
c. 51p, 72n, 51e
Exam 1 Review
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Clark College
15.
Chemistry 131
An atom that has the same number of neutrons as 59Co is
a. 59Ni.
b. 57Co.
c. 60Cu.
d.
e.
58
58
Fe.
Ni.
16.
The atomic mass of Ga is 69.72. There are only two naturally occurring isotopes of gallium, 69Ga with a
mass of 69.0 and 71Ga with a mass of 71.0. The natural abundance of the 71 Ga isotope must be
approximately
a. 20%.
d. 60%.
b. 40%.
e. 80%.
c. 50%.
17.
The neutral atoms of all the isotopes of the same element have
a. different numbers of protons.
d. the same mass numbers.
b. equal numbers of neutrons.
e. the same masses.
c. the same number of electrons.
18.
An element, X, has the following isotopic composition: X-200, 90%; X-199, 8.0%; and X-202, 2.0%. Its
atomic mass is CLOSEST to
a. 199 amu.
d. 202 amu.
b. 200 amu.
e. It cannot be determined.
c. 201 amu.
19.
One gram of TNT, C7H5 N3 O6 , has 7.95 x 1021 nitrogen atoms. How many hydrogen atoms are there in
1.00 g of TNT?
a. 7.95 x 1021
d. 1.59 x 1022
21
b. 9.26 x 10
e. 1.86 x 1022
22
c. 1.33 x 10
20.
The formulas of the carbonate ion, the ammonium ion, and the chlorate ion are represented,
respectively, as
a. CO32-, NH2-, ClO3-.
b. CO32-, NH3+, ClO2-.
c. CO2-, NH4+, ClO-.
21.
22.
d. CO32-, NH4+, ClO3-.
e. P3-, NH3+, ClO2-.
The chemical formula for iron(III) sulfide is
a. Fe2(SO3)3.
b. Fe2(SO4)3.
c. Fe2S3.
d. Fe3(SO3)2.
e. Fe3(SO4)2.
The group(s) that readily form cations is (are) the
1. alkali elements.
2. halogen elements.
3. transition elements.
a. 1 only
b. 2 only
c. 3 only
Exam 1 Review
d. 1 and 2 only
e. 1 and 3 only
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Clark College
Chemistry 131
23.
What is the molar mass of ammonium sulfate, (NH4)2SO4, an important synthetic fertilizer?
a. 70. g/mol
d. 132 g/mol
b. 92 g/mol
e. 146 g/mol
c. 114 g/mol
24.
How many aluminum atoms are there in 25 g of Al2S3?
a. 1.0 x 1023
b. 2.0 x 1023
c. 4.5 x 1023
25.
How many molecules are there in 176 g of ascorbic acid, C6 H8 O6?
a. 88
6.0 x 10 23
e.
b. 176
176
c. 6.02 x 1023
d. 176 x 6.0 x 1023
26.
Sodium cyclamate, C6 H11NHSO3 Na, was used at one time as an artificial sweetener. C6 H11NHSO3Na has
a molecular mass of 201.2 g/mol. How many moles of sodium cyclamate are contained in a 25.6-g
sample?
a. 0.127
d. 7.86
b. 0.193
e. 5180
c. 0.245
27.
Calculate the number of moles of bromine present in 30.0 mL of Br2(l) whose density is 3.12 g/mL.
a. 0.586
d. 2.34
b. 1.17
e. 2.75
c. 1.83
28.
What is the percentage of chlorine in DDT, C14H9Cl5?
a. 35.0
b. 40.0
c. 45.0
d. 4.0 x 1021
e. 6.0 x 1021
d. 50.0
e. 55.0
29.
What is the percentage of mass of oxygen in vanillin, C8H8O3, which is used as a flavoring?
a. 27.3%
d. 63.2%
b. 31.6%
e. 68.4%
c. 45.8%
30.
Analysis of a hydrocarbon showed that it contained 14.4% hydrogen and 85.6% carbon by
weight. What is its simplest formula?
a. CH
b. CH2
c. CH3
Exam 1 Review
d. C2H3
e. C2H5
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Clark College
Chemistry 131
Answers:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
C
B
C
B
C
C
A
E
D
A
Exam 1 Review
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
B
E
C
B
D
B
C
B
C
D
Distributed on Monday, October 7, 2002
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
C
E
D
B
C
A
A
D
B
B
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