All About
Elements:
Oxygen
1
Ward’s All About Elements Series
Building Real-World Connections to
the Building Blocks of Chemistry
PERIODIC TABLE OF THE ELEMENTS
GROUP
1/IA
18/VIIIA
1
H
35
2/IIA
3
Li Be
6.94
Symbol
Na Mg
24.31
19
3/IIIB
20
39.10
40.08
37
44.96
38
Rb Sr
85.47
Y
87.62
55
5/VB
22
132.91
87
39
´
Ac
- Lr
Ac-Lr
Fr Ra
´´
(226.03)
(226)
40
6/VIB
7/VIIB
24
14/IVA
5
10.81
Atomic Weight
13
9
VIIIB
VIII
8
25
26
Al
10
27
11/IB
28
29
12/IIB
30
26.98
31
15/VA
6
C
12.01
14
Si
28.09
32
16/VIA
7
N
14.01
P
15
30.97
33
16.00
S
16
32.07
92.91
72
73
180.95
104
105
9
F
19.00
17
Cl
35.45
34
52.00
54.94
42
55.85
43
44
58.93
58.69
45
63.55
46
47
65.41
48
69.72
49
72.64
50
74.92
51
78.96
78.96
52
Zr Nb Mo Tc Ru Rh Pd Ag Cd In Sn Sb Te
Hf Ta
4.00
17/VIIA
8
O
35
10
Ne
20.18
18
95.94
95.94
(98)
(97.91)
74
101.07
75
76
W Re Os
183.84
106
186.21
107
190.23
108
102.91
77
Ir
192.22
106.42
107.87
78
79
112.41
80
114.82
81
118.71
82
121.76
83
127.60
84
79.90
I
53
126.90
85
39.95
36
83.80
54
Xe
131.29
109
196.97
110
111
200.59
112
204.38
113
207.2
207.20
114
208.98
115
(208.98)
(209)
116
(209.99)
(210)
117
(222.02)
(222)
118
Rf Db Sg Bh Hs Mt Ds Rg Uub Uut Uuq Uup Uuh Uus Uuo
(261)
(261.11)
´
(262)
(262.11)
57
(266)
(266.12)
58
(264)
(264.12)
59
(277)
(277.00)
60
61
(268)
(268.14)
(269)
(247.07)
62
63
(272)
(280.00)
64
(285)
(285.00)
65
(284)
(284.00)
66
(289)
(289.00)
67
(288)
(288.00)
68
(289)
(293.00)
69
(294.00)
70
(294)
(294.00)
71
La Ce Pr Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu
138.91
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´´
© 2010 Rev. 7/15 Ward’s Science. All Rights Reserved.
No portion of this work may be reproduced in any form
or by any means without express prior written permission
from Ward’s Science.
US: www.scholarchemistry.com
Canada: www.scholarchemistry.ca
866-260-0501
89
© Copyright 2010 ScholAR Chemistry. All Rights Reserved.
140.91
90
91
Ac Th Pa
(227)
(227.03)
NOTES:
BASIC
PERIODIC
- SIDE 1 (Rev.
7/15)
No portion
of this workTABLE
may be reproduced
in any form
or by any means
140.12
232.04
232.04
Black — solid
Red — gas
231.04
Blue — liquid
144.24
U
92
238.03
(145)
(144.91)
93
150.36
151.97
151.96
94
157.25
95
96
158.93
97
162.50
98
164.93
99
167.26
100
168.93
101
173.04
(244)
(244.06)
(243)
(243.06)
(247)
(247.07)
(247)
(247.07)
(251)
(251.08)
(252)
(252.08)
(257)
(257.10)
(258)
(258.10)
102
(259)
(259.10)
3.The ozone layer in the stratosphere, which
protects us from UV radiation, is only an average of 3mm thick.
O
8
15.999
174.97
103
Np Pu Am Cm Bk Cf Es Fm Md No Lr
(237)
(237.05)
2.The oxygen that’s produced as a result of
photosynthesis is derived from the water
absorbed by plants, not the carbon dioxide.
86
Pt Au Hg Tl Pb Bi Po At Rn
195.08
1.Oxygen constitutes 21% of our atmosphere,
nearly half the mass of the earth’s crust and
about two thirds of the human body. It is the
third most abundant element in the universe
after Helium and Carbon.
Ar
Cr Mn Fe Co Ni Cu Zn Ga Ge As Se Br Kr
41
178.49
88 89–103
23
50.94
91.22
57–71
La-Lu
137.33
V
47.87
88.91
56
Cs Ba
(223.02)
(223)
4/IVB
21
Ca Sc Ti
13/IIIA
B
79.90
12
22.99
Atomic Number
Br
4
9.01
11
K
He
KEY
1.01
2
Fun Facts
About…
Oxygen
(262)
(262.11)
— synthetically prepared
Values provided are based on the 85th edition of the CRC Handbook of Chemistry and Physics. Some values have been rounded.
without express prior written permission from ScholAR Chemistry.
4.Under controlled conditions, the three most active metals (potassium, rubidium, and cesium)
can react with oxygen to form oxides (M2O), peroxides (M2O2) and superoxides (MO2).
Catalog #9630200
The periodic table of elements is an essential part of any chemistry classroom
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of substances in our universe can be tied back to just these 118 simple, yet
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5.When water is boiled to kill bacteria, it drives out all dissolved gasses including oxygen. Therefore, aquatic life like goldfish and other freshwater fish cannot survive in water that’s been
previously boiled and then cooled. Water must be aerated before adding fish!
All About Oxygen:
Oxygen gas is essential for life on earth as
we know it. It is the element that allows us
to create the energy that enables us to live.
Oxygen is the 8th element on the periodic
table, located in Group VIB, with an electron
configuration 1s2 2s2 2p4. It is classified as
a non-metal, which means it reacts readily
with metals, usually gaining two electrons
to form metal oxides. These oxides, when
dissolved in water, produce basic solutions.
Oxygen can also react with other nonmetals, sharing two of its valence electrons
in covalent bonds. These non-metal oxides,
such as sulfur dioxide, form acidic solutions.
An oxygen atom bonds with another oxygen
atom to form the familiar oxygen gas, O2, but it can also exist as the triatomic element, ozone, or
O3. At room temperature and pressure, oxygen, O2, is a colorless, odorless gas. The structure for O2
as usually written with a double bond between the oxygens. This however is incorrect! Molecular
orbital calculations show us that O2 has two degenerate antibonding orbitals each containing one
electron. The O2 molecule is therefore considered to be a diradical or triplet in its ground state.
Check back often at wardsci.com/elements for the latest content
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2
3
Properties of Oxygen
Physical evidence for this diradical structure comes from the properties of liquid oxygen. It is blue
in color and highly paramagnetic, both consistent with free radical structures.
Commercial Production
Oxygen can be obtained from the atmosphere by
the fractional distillation of air. Air is first cooled and
liquefied. This liquid air is a mixture of liquid nitrogen, boiling point -196 ˚C, and liquid oxygen, boiling
point -183˚C. The nitrogen, with its lower boiling
point, evaporates first. Fractionation of the mixture
will yield pure liquid oxygen after the nitrogen has
evaporated. The oxygen is converted to gas and the
gas is distributed as a compressed gas in high pressure cylinders.
Reactions of Oxygen
Discovery and History
Scientists believe that oxygen has been in Earth’s atmosphere for around 2.3 billion years. Life
on Earth is thought to have started at least 3.5 billion years ago. The buildup of oxygen in the
atmosphere may have been due to a decrease in geologic activity, which used up the oxygen produced by photosynthesis of some simple bacteria. Clearly oxygen was required for more complex
life forms to develop.
The first awareness of oxygen gas by humans occurred in 1608 when the Dutch inventor, Cornelius Drebbel found that when he heated saltpeter, KNO3, a gas was produced. The identity of this
gas remained unknown until the 1770s when Joseph Priestly of England, Carl Wilhelm Scheele of
Sweden, and Antoine-Laurent de Lavosier of France each worked with it. Lavosier discovered the
role oxygen plays in respiration and combustion. He named the gas oxygen, which comes from
the Greek “oxy” meaning acid and “gene” meaning producing.
Synthesis of Oxygen In the Lab
In the laboratory, there are a number of ways for oxygen to be produced. The decomposition of
either potassium chlorate or potassium permanganate produces oxygen gas. The gas can be easily collected by water displacement.
2KClO3 (400°C) --> 2KCl + 3O2
2KMnO4 (214°C) --> K2MnO4 + MnO2 + O2
The standard test for oxygen gas is to insert a glowing splint into a test tube containing the gas. If
the splint bursts into flames, the gas is almost certainly oxygen. The decomposition of hydrogen
peroxide is easily carried out in the lab, which also produces oxygen.
NaOCl(aq) + H2O2(aq) --> NaCl(aq) + H2O(l) + O2(g)
Oxygen can also be prepared by the electrolysis of acidified water. The
Hoffman electrolysis apparatus, which is shown below, demonstrates this
in a laboratory setting.
An electric current passed through a diluted sulfuric acid solution will
produce oxygen at the anode, by oxidation of water, and hydrogen at the
cathode, by the reduction of water. The ratio of the oxygen to hydrogen
produced is 1:2, which can clearly be seen using this device.
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4
Oxygen can be obtained from the atmosphere by
the fractional distillation of air. Air is first cooled and
liquefied. This liquid air is a mixture of liquid nitrogen, boiling point -196 ˚C, and liquid oxygen, boiling
point -183˚C. The nitrogen, with its lower boiling
point, evaporates first. Fractionation of the mixture
will yield pure liquid oxygen after the nitrogen has
evaporated. The oxygen is converted to gas and the
gas is distributed as a compressed gas in high pressure cylinders.
Uses of Oxygen
Oxygen in the air is essential for respiration of most
animals in order to produce energy. The oxygen
atoms are returned to the atmosphere in the form of
carbon dioxide. The largest commercial consumption of oxygen is in the steel industry where it is
used in blast furnaces to increase the temperatures
of the furnace. Oxygen is also used in electric arc
furnaces used to melt scrap metal and in oxy-acetylene torches. Large quantities of oxygen are used
in the manufacture of a number of chemicals. These
include nitric acid, hydrogen peroxide, epoxyethane
(ethylene oxide), used as antifreeze, and ethylene
chloride, the precursor for polyvinyl chloride.
The oxygen tanks you see in the hospital provide
an increased concentration of oxygen for patients
who may have some difficulty breathing. Sparks near
oxygen tanks are dangerous, not because oxygen is
flammable, but because oxygen promotes burning. A small spark can become a big fire.
Oxygen is sparingly soluble in water, but the small quantity of dissolved oxygen is essential to
the life of fish. Since gases are more soluble in cold water than in hot water, thermal pollution, or,
the addition of hot water to streams and lakes, can cause fish to die due to a lack of oxygen. To
prevent harm to aquatic life, industrial and power plants use billions of gallons of water to cool
the water they use before releasing it back into lakes, rivers, and streams.
5
Peroxides and Superoxides
Ozone
Oxygen’s oxidation number in most compounds is -2. Interestingly, oxygen can also form compounds in which
its oxidation number is -1 and even –½. In peroxides, the
simplest of which is hydrogen peroxide, an O-O bond
results in an oxidation number for oxygen of -1. When
hydrogen peroxide decomposes it forms oxygen gas.
Alkyl peroxides, R-O-O-R are often used as initiators for
free radical reactions, including some polymerization
reactions. The O-O bond breaks homolytically to form
two radicals.
Ozone is an allotrope of oxygen that exists as three oxygen atoms bonded together to form O3. It
occurs naturally in the upper atmosphere and is formed in the lower atmosphere during electrical
storms. At room temperature it is a pale blue gas with a pungent odor. It forms a dark blue liquid
at -112°C and freezes to a purple solid at -193°C.
The most active metals, K, Rb, and
Cs can react with oxygen to form
superoxides. The oxygen in the O2-1
anion in KO2 has a formal oxidation
number of –½ . When these superoxides dissolve in water, oxygen gas
is produced. Potassium superoxide
is used in gas masks worn for rescue
work. Moisture in the breath converts
the superoxide to the oxygen needed for respiration.
Ozone in the stratosphere, the upper atmosphere, is essential for protecting us from harmful UV
radiation. Most high energy radiation (<240nm) is absorbed by oxygen gas to produce ozone.
However, UV radiation between 240nm and 290nm is not absorbed by oxygen and would be
harmful to life on earth were it not absorbed by ozone.
Ozone is an extremely reactive form of oxygen. It is second in strength to fluorine as an oxidizing
agent. It is used commercially to bleach textiles and certain kinds of oils and is also a very effective germicide that can be used to sterilize air and water. In fact, ozone generators are available
for hot tubs in order to keep them germ free. Unfortunately, ozone’s high reactivity causes irritation of the nose and throat and decomposition of rubber and plastics.
240–290nm
2O3
Tube of Toothpaste Demonstration (Catalytic
Decomposition of Hydrogen Peroxide)
Ward’s Item Number 2005600
Oxygen and Photosynthesis
During photosynthesis, plants take in carbon dioxide to produce carbohydrates and eliminate
oxygen gas. Red and blue light is absorbed by the green chlorophyll in the plants (green light is
reflected) in order for the process to occur.
3O2
<240nm
In the past, chlorofluorocarbons used as coolants,
in spray cans, fire extinguishers and cleaning products were responsible for depleting the protective
ozone layer, particularly over the north and south
poles. This ozone layer has begun to be renewed
because of government limitations on the use of
these materials.
sunlight
6CO2 + 6H2O ——> C6H12O6 + 6O2
chlorophyll
It is often said that plants convert carbon dioxide to
oxygen. This is not completely correct. The oxygen that
plants produce and that we breathe actually comes
from water. The first steps in the photosynthetic process
are the absorption of light and the conversion of the
light energy into chemical energy. The oxygen atoms in
the water molecules are oxidized to form oxygen gas,
which is eliminated. This only happens in daylight.
Too little there…Many popular consumer products like air conditioners and refrigerators involve CFCs or halons during
either manufacture or use. Over time, these chemicals damage the earth’s protective ozone layer.
2H2O –> 4e– + 4H+ + O2
The high energy of the electrons produced is used to
make the carbohydrates. Seventy five years ago scientists1 showed that when water containing oxygen-18
was “fed” to plants, all of the labeled oxygen ended up
in the oxygen gas eliminated, and none was found in the carbohydrates produced. Therefore, it
was concluded that carbohydrates come from carbon dioxide and oxygen comes from water.
1. Ruben, S., M. Randall, M. D. Kamen, and J. L. Hyde. (1941) “Heavy oxygen (O18) as a tracer in the study of photosynthesis.” Journal of the American Chemical Society, Vol. 63, pp. 877–879.Peroxides and Superoxides
6
Too much here…Cars, trucks, power plants and factories all
emit air pollutino that forms ground-level ozone, a primary
component of smog.
7
On the other hand, ozone in the lower atmosphere is harmful to human health. It damages
vegetation and corrodes many materials. Ozone is an important ingredient of smog. Vehicles and
some manufacturing plants emit air pollution that forms ozone. Inside the hot cylinders of internal combustion engines, nitrogen and oxygen can react to form nitrogen oxide, NO (equation 1).
The NO reacts with oxygen in the air to form NO2 (eqation 2). In the presence of bright light, the
NO2 dissociates to form the oxygen radical (equation 3), which can react with more O2 to form
ozone (equation 4).
N2(g)
+ O2(g)
1
2
–> 2NO(g)
2 NO(g) + O2(g) –> 2 NO2(g)
NO2(g)
+ light –> NO(g) + O(g)
3
4
O(g) + O2(g)
–> O3(g)
Teach All About Oxygen with
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gases from vehicles, power plants and manufacturing sites and thereby limit harmful ozone.
Ward’s® Photosynthesis
Demonstration
Simple Yet Versatile, For A Variety Of Investigations
• Demonstrate Photosynthesis On An Overhead
Or Document Camera
• Works With Aquatic Or Terrestrial Plants
Easily demonstrate quantitative examples of photosynthesis and various environmental effects on
plants with WARD’S photosynthesis apparatus. The
variety of suggested experiments work with either
aquatic plants or terrestrial plants. You can change
the variables affecting photosynthesis and measure the rate of oxygen emitted as a byproduct, or
test the influence of light intensity and wavelength, carbon dioxide and oxygen concentration
in water, and other environmental factors. You can
even place the apparatus on the overhead projector so the entire class can see the demonstrations.
The model comes with a chamber, set of three
color filters, set of three light-limiting bars, and
instructions with suggested activities that can be
performed with the apparatus.
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Item Number: 470300-688
Determination of
Dissolved Oxygen Kit
Determination of Dissolved Oxygen kit, 40 tests,
Kit Contents: 4 Plastic Pipettes, 3 Reaction Vessel,
3 Collection Bottle, 2 Titrator, 30mL Manganese
Chloride Reagent 30mL Alkaline Iodide Reagent,
30mL 50% Sulfuric Acid, 60mL Sodium Thiosulfate
Titrant
Item Number: 470146-436
9
Ward’s® What’s Up With
the Ozone Lab Activity
Test Your Local Area for Ozone
Conditions
•
Designed for AP level students
•
Practice preparing test strips
•
Includes a teacher’s guide
The differentiation of ozone levels within the
same general vicinity is explored in this AP level
lab. Students prepare their own test strips and
carry out tests for tropospheric ozone pollution.
They then analyze the results for local variation
and possible impact on human health. Includes
a teacher’s guide, student copymasters, and
materials for six setups.
Item Number: 360913
Ward’s® Effects of Solar
UV Radiation on Cells
Lab Activity
Dramatic Results Mimic Effects of
Sun on Living Tissue
•
Demonstrate the effects of solar radiation
•
Apply concepts to themselves
•
Estimated class/lab time required:
45 minutes
Do sunscreens and sunglasses really work to
block damaging UV rays? Your class treats the
lid of a Petri dish containing a sun-sensitive
yeast strain with sunscreen or covers part with
sunglasses, leaving part exposed to ultraviolet
radiation from the sun. After incubating the
plate, students can gauge the effects of the
sun on the yeast cells, applying their findings
to humans as well. Other simple experiments
explore additional factors such as the angle
of the sun, ozone depletion, and air pollution.
Includes enough materials for 24 students.
Note: Coupon included for perishable materials.
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Item Number: 853519
Up in Vapor!
Hydrogen Peroxide
Decomposition
In this experiment you will show the decomposition of the chemical hydrogen peroxide
using sodium iodide.
Kit Includes:
1 x 350 ml Hydrogen Peroxide, 30% UN2014
7 x 4 g Sodium Iodide.
Item Number: 470163-150
Hydrogen Peroxide
CAS Number: 7722-84-1
Formula Weight: Mixture
Formula: Mixture
Density (g/mL): Approximately 1.0
Boiling Point (°C): Approximately 100
Freezing Point (°C): Approximately 0
Solubility: Water and Alcohol
Synonyms: Hydrogen Dioxide
Shelf Life (months): 12
Storage: White/Green
Please Note: This product is designed for educational
and teaching laboratories, and no certificate of
analysis is available..
Item Number: 470301-288
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10
Tube Of Toothpaste Demo
Hoffman Electrolysis
Apparatus
The Hoffman Electrolysis Apparatus is used for the
qualitative and quantitative study of the electrolytic
decomposition of electrolytes such as water and
hydrochloric acid. Tubes are 50mm each. Included
platinum electrodes are also sold separately.
Includes activity guide. Contents: 1 Support Stand,
1 Burette Clamp, 1 Extension Clamp, 1 Bosshead
Clamp, 1 Pair of Platinum Electrodes, 1 Pair of
Carbon Electrodes, 1 Activity guide.
Item Number: 470213-364
Take the decomposition of hydrogen peroxide
to a new level by adding soap and food coloring.
Now the oxygen and heat are trapped in a rapidly
expanding foam column that quickly flows out
of the tube. Demonstrate the production of pure
oxygen gas by using a glowing splint to “ignite”
the bubbles. Observing this colorful and crazy
demonstration, students will learn about catalysts,
decomposition reactions, exothermic reactions,
gas volume, and the properties of oxygen.
Item Number: 470213-364
11
Content Contributed by Joe Simson
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