Download Review for Unit 2A Test

ADDITIONAL REVIEW – UNIT TEST 2A -- CHEMISTRY
GENERAL NOTES: Recall that the test covers what we have done in class as well as all of Chapters 2 and 3,
average atomic mass, and any earlier material.
1. State/define:
Law of Conservation of Mass
Law of Conservation of Energy
Law of Definite Proportions
Law of Multiple Proportions
atomic number
Mass number
isotopes
average atomic mass
additional vocabulary
2. Give 2 examples of each:
Physical change
Chemical change
3. A sample has a mass of 3.17g. A balance was used to mass the sample, and the following were obtained: 3.56g,
3.55g, and 3.57g.
Are these data precise?
Are they accurate?
4. Estimate:
The volume of a drinking glass
The mass of a goldfish
The length of a school bus
Your mass in kg
The volume of your locker
The length of your shoe
5. Chromotography is used to:
6. Compute Rf values for each substance shown in the chromatogram below.
start
A
B
C
D
solvent front
│
▐
▐
▐
▐
│_______
7. Which substance (above) has molecules that spend the most time in the
mobile phase?
8. A sample of a mineral has a mass of 64g and a volume of 32 cm3. What is the density of this mineral?
A. .20 g/cm3
B. 2.0 g/cm3
C. 5.0 g/cm3
D. .50 g/cm3
8B. Will it sink?
How do you know?
9. An element is made of only one kind of:
A. compound
B. atom
C. molecule
D. mixture
10. When doing unit conversions, ________ MUST always be done first!
A. numbers
B. units
C. calculations
D. answers
FOR #11 – 16: Use the answers at the right.
11. aluminum
12. chili
13. orange juice (w/ pulp)
14. salt water
15. salt (sodium chloride)
16. sulfur dichloride
Classify each material as:
A. element,
B. compound,
C. homogeneous mixture,
D. heterogeneous mixture.
17. Review EXCEL: addresses, formulas, graphing…
18. There are ____ centigrams in 22.3g.
19. There are ____ milliliters in .98 liters.
20. There are ____ meters in 12.8km.
21. Review the development of the atomic theory: the “who, what, when etc.” of each of the steps in its
development, through Rutherford. The following will help with this.
The four centers of early civilization were: ___________, ____________,
_______________, and the ____________ __________. Western civilization
traces its roots to _________.
The __________ empire "took over from" or
"built on" the Greek empire and peaked around the year __________. The
__________ Ages began after this empire collapsed and lasted from
approximately 500AD to approximately _____________. During the latter part
of the Dark Ages, Alchemists tried to _____________________________________
and ___________________________________. Lasting influences of their ideas
include (list 4 or 5): ________________________________________
____________________________________________________________________.
Lasting benefits from the Alchemists include: _______________________,
_____________________________, and ____________________________. Then began
that great age known as the Renaissance (which means ____________), when
people began to ________ for themselves.
In approximately 400 BC ______________ stated the first atomic theory.
For almost 2200 years there was not an atomic theory because _____________
had disagreed with the idea of atoms. Finally, around the year 1800,
______________ brought back the atomic theory. This time, the theory was
based on experimental ________________. The ideas included in this theory
were that: "All matter is composed of ____________."; "Atoms of the same
element are the ________ and atoms of different elements are
_______________."; "Atoms are rearranged in chemical _______________."; and
"Atoms can be combined in small whole number ratios to form ___________."
Then, in the 1890's, ____________ discovered and described the electron,
which is smaller than an atom, and is part of every atom. Thomson was
working with a special tool called ________________________. Two modern uses
of CRT's include _____________________ and _____________________. Thomson's
model of the atom is also referred to as the __________________ model of the
atom.
Not on the test, but: Millikan built on Thomson's work and discovered
the ____________ and _____________ of the electron.
Using gold foil, ________________ determined that most of the mass and
positive charge of the atom are concentrated in the central ________.
22. Complete the following tables:
Name
symbol
atomic #
mass #
# protons
# electrons
# neutrons
Sulfur-35
17
21
212
Po
42
Name
symbol
atomic #
mass #
55
# protons
# electrons
# neutrons
Iodine-130
30
122
35
Sn
80
90
23. Review the properties of electrons, protons, and neutrons, as well as vocabulary.
24. What determines the chemical behavior of atoms? _______________________________
25. Carbon occurs in nature as a mixture of two isotopes, carbon-12 and carbon-13. Explain how atoms of these
two isotopes are the same, and how they are different:
26. The average atomic mass of neon is 20.179 amu. This indicates that atoms of neon contain:
A. .179 of a proton
B. .179 of a neutron
C. .179 of an electron
D. none of the above
27. Copper is composed of two isotopes, copper -63 and copper-65. The average atomic mass of copper is 63.456
amu. How do the natural abundances of the two isotopes compare?
A. Copper -63 is more abundant
B. The abundances are the same
C. Copper -65 is more abundant
D. Can't be determined from the given data
PROBLEMS -- ADDITIONAL F-L PROBLEMS ARE ALSO IN AN EARLIER REVIEW.
1. What mass of salt would be present in 54.7g of a 12.0% NaCl (salt) mixture?
2. Calculate the volume of 78.5g of iron. DFe = 7.87 g/cm3
3. Determine the volume of brass needed to make 3400 .443 pound figurines. The density of this brass is 8.77
g/cm3, and there is 5.0% waste in the manufacturing process.
4. A 34.2g ring is 58.0% copper and 42.0% gold. USING FACTOR-LABEL, Find the mass of gold in the ring.
5. The element Pennsylvanium (Pn) is composed of two naturally occuring isotopes, as shown. Compute the
average atomic mass of Pennsylvanium:
Isotope
Pn-102
Pn-104
Mass (u)
201.988
203.982
% abundance
54.22
45.78
ADDITIONAL REVIEW – UNIT TEST 2A -- CHEMISTRY
GENERAL NOTES: Recall that the test covers what we have done in class as well as all of Chapters 2 and 3,
average atomic mass, and any earlier material..
1. State/define:
Law of Conservation of Mass
Law of Conservation of Energy
Law of Definite Proportions
Law of Multiple Proportions
atomic number
Mass number
isotopes
average atomic
additional vocabulary
2. Give 2 examples of each:
Physical change
Any change that results in the same substance(s), NOT chemically changed. Common examples
are phase changes, such as melting, freezing, etc.
Chemical change
Any change that results in the creation of new substances.
3. A sample has a mass of 3.17g. A balance was used to mass the sample, and the following were obtained: 3.56g,
3.55g, and 3.57g.
Are these data precise? yes
Are they accurate? no
4. Estimate:
The volume of a drinking glass
The mass of a goldfish
The length of a school bus
Your mass in kg
The volume of your locker
The length of your shoe
5. Chromotography is used to:
400 ml
25 g
20 m
Kudrick is pushing 100 kg
120 L
30 cm
Separate components of a mixture
6. Compute Rf values for each substance shown in the chromatogram below.
start
A
B
C
D
solvent front
│
▐
▐
▐
▐
│_______
.28
.41
.63
.75
7. Which substance (above) has molecules that spend the most time in the
mobile phase? D
8. A sample of a mineral has a mass of 64g and a volume of 32 cm3. What is the density of this mineral?
A. .20 g/cm3
B. 2.0 g/cm3
C. 5.0 g/cm3
D. .50 g/cm3
8B. Will it sink? yes
How do you know? Density is greater than water’s (1.0g/cm3)
9. An element is made of only one kind of:
A. compound
B. atom
C. molecule
D. mixture
10. When doing unit conversions, ________ MUST always be done first!
A. numbers
B. units
C. calculations
D. answers
FOR #11 – 16: Use the answers at the right.
11. aluminum
12. chili
13. orange juice (w/ pulp)
14. salt water
15. salt (sodium chloride)
16. sulfur dichloride
A
D
D
C
B
B
Classify each material as:
A. element,
B. compound,
C. homogeneous mixture,
D. heterogeneous mixture.
18. There are _2230___ centigrams in 22.3g.
19. There are __980__ milliliters in .98 liters.
20. There are _12 800___ meters in 12.8km.
21. The four centers of early civilization were: __China__, __India___,
___Egypt____, and the __Middle__ __East___. Western civilization traces its
roots to __Greece__. The _Roman______ empire "took over from" or "built on"
the Greek empire and peaked around the year ___0____. The ___Dark___ Ages
began after this empire collapsed and lasted from approximately 500AD to
approximately __1500 AD____. During the latter part of the Dark Ages,
Alchemists tried to __change cheap stuff into gold__ and __discover
immortality___. Lasting influences of their ideas include (list 4 or 5):
_Midas, Rumpelstiltskin, Goose that laid the Golden Egg, Ponce de Leon, Harry
Potter, etc_. Lasting benefits from the Alchemists include: _chemical
techniques_, __chemical equipment__, and _new elements __. Then began that
great age known as the Renaissance (which means __rebirth_), when people
began to __think_ for themselves.
In approximately 400 BC _Democritus___ stated the first atomic theory.
For almost 2200 years there was not an atomic theory because _Aristotle__ had
disagreed with the idea of atoms. Finally, around the year 1800, __Dalton__
brought back the atomic theory. This time, the theory was based on
experimental __evidence, data__. The ideas included in this theory were
that: "All matter is composed of ___atoms__."; "Atoms of the same element
are the __same__ and atoms of different elements are __different__."; "Atoms
are rearranged in chemical __reactions__."; and "Atoms can be combined in
small whole number ratios to form _compounds_." Then, in the 1890's,
_Thomson__ discovered and described the electron, which is smaller than an
atom, and is part of every atom. Thomson was working with a special tool
called _cathode ray tube___. Two modern uses of CRT's include __TVs_ and
_computer monitors___. Thomson's model of the atom is also referred to as
the _Plum Pudding__ model of the atom.
We skipped him, but: Millikan built on Thomson's work and discovered
the __charge__ and __mass___ of the electron.
Using gold foil, __Rutherford__ determined that most of the mass and
positive charge of the atom are concentrated in the central _nucleus__.
Name
symbol
atomic #
mass #
# protons
# electrons
# neutrons
Sulfur-35
35
16
35
16
16
19
Chlorine-38
Polonium-212
Molybdenum-97
38
17
84
42
38
212
97
17
84
42
17
84
42
21
128
55
S
Cl
Po
97
Mo
212
Name
Iodine-130
symbol
130
I
Zinc-65
65
Tin-122
Mercury-170
122
atomic #
53
mass #
130
# protons
53
# electrons
53
# neutrons
77
30
65
30
30
35
50
80
122
170
50
80
50
80
72
90
Zn
170
Sn
Hg
24. What determines the chemical behavior of atoms? ___electrons. More specifically: outer electrons__
25. SAME: number of protons, number of electrons, chemical behavior
DIFFERENT: numbers of neutrons, masses, stability
26. D. none of the above
27, A. Copper -63 is more abundant
PROBLEMS -- ADDITIONAL F-L PROBLEMS ARE ALSO IN AN EARLIER REVIEW.
1. What mass of salt would be present in 54.7g of a 12.0% NaCl mixture?
Convert
54.7g mixture (solution, total)
54.7g mixture
/
12.0 g NaCl
/
100 g mixture
2. Calculate the volume of 78.5g of iron.
V = m/D
to
g NaCl.
=
6.56 g NaCl.
DFe = 7.87 g/cm3
V = 78.5g/7.87 g/cm3
V = 9.97 cm3
3. Determine the volume of brass needed to make exactly 3400 .443 pound
figurines. The density of this brass is 8.77 g/cm3, and there is 5.0% waste
in the manufacturing process.
Convert
3400 figurines
3400 fig.
needed
/ .443 lb /
/
to
1 kg
1 fig. / 2.205 lb /
L brass.
/ 1000 g
1 kg
/ 1 cm3
/
/ 8.77 g /
1 L brass used
1000 cm3
/ 100 L brass
/
95.0 L brass
used
= 82.0 L brass needed
4. A 34.2g ring is 58.0% copper and 42.0% gold. Calculate the mass of gold in the ring. 14.4g Au
5. The element Pennsylvanium (Pn) is composed of two naturally occuring isotopes, as shown. Compute the
average atomic mass of Pennsylvanium:
Isotope
Pn-102
Pn-104
Mass (u)
201.988
203.982
% abundance
54.22
45.78
202.9u