The Précis of Cobalt
Jessie Allen
December 17, 2010
Ever thought about what the Earth’s crust is composed of? Among a lot of other
elements, cobalt makes up only 0.003 percent of it. Cobalt is also an element that would be
considered very rare. Cobalt is not naturally found pure in nature, but does have a lot of
information about it in the following categories: background, characteristics, chemical
properties, interesting facts, and the written separation scheme.
Many scientists had found out that people around the world, like the Egyptians, have
been using cobalt compounds for many centuries. But it was not until 1739 when a Swedish
chemist actually isolated the element cobalt (Stwertka 92). This chemist’s name was Georg
Brandt (92). “One of its major ores is called cobaltite, a compound of cobalt, arsenic, and sulfur.
The pure metal, with its characteristic bright bluish-white color, is obtained by roasting this ore
in air” (Stwertka 92). This is how Brandt discovered cobalt, by roasting this ore with air. The
name cobalt comes from the word kobold which is German and means that it is an evil spirit or
an evil gnome (Stwertka 92). The symbol for cobalt is Co. The atomic number of it is 27 and the
true atomic mass of cobalt is 58.9332 (“Cobalt, Chemical Element”). Cobalt is classified on the
periodic table as “a transition metal, one of several elements found in Rows 4 through 7 between
Groups 2 and 13 in the periodic table”(“Cobalt, Chemical Element”). It is also in between the
elements of iron and nickel. Because it is placed in between the two of these elements, it shares
some of the same physical properties and chemical properties as them. The natural phase that
cobalt occurs in is a solid. The melting point of cobalt is 1768 K (1495 degrees C). Also the
boiling point of it is 3203 K (2930 degrees C) (Winter). “Cobalt is a hard, gray metal that looks
much like iron and nickel. It is ductile, but only moderately malleable. …cobalt is one of only
three naturally occurring magnetic metals. The other two are iron and nickel” (Cobalt, Chemical
Element).
Because of its general occurrence in nature and its geographical location, cobalt has many
different characteristics. Cobalt is not found as a pure element when naturally out in nature. But,
it can be found in several types of minerals such as erythrite, smaltite, cobaltite, safflorite,
skutterudite, and many others. It is also found in ores along with metals such as silver, copper,
nickel, iron, and lead. Cobalt can also be found in meteorites (“Cobalt Facts”). The percent
abundance of cobalt in the earth’s crust is 20 parts per million (Barbalace). Some of the
compounds containing cobalt are very important. An example would be cobalt oxide. “This
substance, usually prepared by heating the cobaltic hydroxide that is precipitated from cobaltcontaining solutions by sodium hypochlorite, has a number of important uses in the glass and
ceramics industries. Cobalt oxide additions of 140 to 4,500 grams (5 ounces to 10 pounds) per
ton of glass are made to impart a blue colour to structural glass, bottles, and optical filter
glasses…”(“Cobalt Processing”). Lithium cobalt oxide is another compound that is very
important to today’s life. Lithium cobalt oxide is used in the positive electrodes of lithium ion
batteries (“Characterization…”). Dicobalt edetate is another compound that is important in the
medical field. It is used as an antidote for cyanide poisoning (Hillman, Bardhan, Bain). Annually
the world produces about 17,000 tons of cobalt (Barbalace). Major mining areas for cobalt can
be found in the countries of Zaire, Morocco, Sweden, and Canada (Barbalace).
The atomic structure of cobalt can be broken down into neutrons, protons, and electrons.
The number of protons and electrons are the same, which means cobalt has 27 of each
(Barbalace). Cobalt also contains 32 neutrons when in its normal state (Barbalace). The crystal
structure of cobalt is hexagonal (Barbalace) (See Appendix A). The atomic radius can be defined
as 1.67Å (Barbalace). The symbol Å is defined as an Ångstrom which is one tenth of a
nanometer (Barbalace). One and sixteenth hundreds Å is what tells you what the covalent radius
is (Barbalace). The atomic volume is 6.7cm3/mol (Barbalace). The electron configuration of the
element cobalt is as follows, [Ar] 3d7 4s2 (“Cobalt Facts”). Cobalt as four different energy levels,
on the first it has two electrons, on the second it has eight, on the third it has 15, and on the last is
has two valence electrons (Barbalace) (See Appendix B). The two valence electrons can be
shown in the Lewis Dot Diagram which can be seen in Appendix C. The oxidation numbers for
cobalt are a minimum of -1 and a maximum of +5 (Winter). But the most common oxidation
numbers for the element cobalt is a minimum of 0 and the maximum for it is +3. Cobalt has
many different isotopes (See Appendix D). Out of that list the most common isotope of cobalt is
Co-59, which occurs naturally and is also stable. All except Co-48, Co-49, and Co-51 are
radioactive isotopes (“Cobalt Facts”).Unlike some elements in the periodic table that react
vigorously with air and water, cobalt does not. They only way it reacts with water is if the metal
is heated then mixed with water. When this happens it creates steam and Cobalt Oxide. The
equation for that is 2Co(s) + O2(g) --> 2CoO(s). Also the only way it reacts with air is if it is
heated which then it creates the oxide Co3O4. The equation for that is 3Co(s) + 4O2(g) -->
2Co3O4(s). Cobalt does react well with halogens. Some examples would be cobalt (II) chloride
(CoCl2), cobalt (II) bromide (CoBr2), and cobalt (II) iodide (CoI2). Each of these can be made
when the metal cobalt reacts with bromine, iodine, or chlorine. The equations for these reactions
are as follows: Co(s) + Br2(l) --> CoBr2(s), Co(s) + Cl2(g) --> CoCl2(s), and Co(s) + I2(s) -->CoI2(s). Cobalt with also react with acids, when mixed with a sulfuric acid, the cobalt metal
will slowly dissolve. The equation for this is Co(s) + H2SO4(aq) --> Co2+(aq) + SO42-(aq) + H2(g)
(“Chemical Properties”).
Cobalt, pure or with it compounds, has many ways it can be used throughout out the
world. Industrially it can be used as alloys in industry, electroplating, and for alternative energy
sources (Rowan). When being used as alloys in industry, they use superalloys which contain
cobalt, to make gas turbine engines and jet engines (Rowan). Also Alnico, an alloy containing
aluminum, cobalt, and nickel, forms strong magnets (Rowan). These magnets are used in airbag
systems in cars, hearing aids, microphones, and compasses (Rowan). Stellite, another alloy that
contains cobalt along with tungsten and chromium, is used to make cutting tools (Rowan). Also
cobalt can be used for an alternative energy sources such as improving rechargeable batteries and
being part of the battery systems in hybrid cars (Rowan). Cobalt is also used in the medical field.
Recently European researchers have found that adding a cobalt complex to an aspirin can change
the molecule’s anti-cancer properties significantly (Brindley). This research is underlining the
potential for discovering of new ways of therapies in anti-tumor by adding fragments of
organometallic that will establish drugs (Brindley). It also can help fight cancer. The isotope Co60 is radioactive and gives off gamma rays (Rowan). Cobalt can also be used as implants, in fact
the Idaho Cobalt Project says about 70% of hip replacements use cobalt in them (Rowan). Art is
another way that cobalt is used today. The cobalt salts are used to produce shades of blue paint
(Rowan). Because the use of cobalt is starting to go up when being used so much in batteries and
for medical reasons, the price of the metal is starting to go up (Montgomery).
In terms of separation and writing the scheme for the formula of Pb2+Ni2+Co2+Li1+ (aq) +
H2O, one must then find different elements or ions that will combine with each of the elements
stated above and form them into a solid. The way to make them into a solid and separate them is
by finding an ion or element that will only combine with one of the other metals. If it combines
with any others in the group then the process will not work. After finding which ions work with
each of the elements, start to separate them (See Appendix E). The first one taken out should be
lead. To make lead a solid, insert bromide to the liquid solution (Welcome to Professor Meyer).
After a while it will form lead bromide, in solid form. Take out the solid and insert it into a
separate test tube. The next metal to be extracted is nickel, to do this insert carbonate in the
liquid solution (Solubility Chart). After a while it will turn into nickel carbonate, a solid. Then
remove that solid and insert it into its own separate test tube. After those two are removed there
are two left, lithium and cobalt. To remove cobalt from the liquid solution, insert hydroxide to
the solution and after a while the solid cobalt hydroxide appears (Welcome to Professor Meyer).
Then insert it into its own separate test tube also. Now the only thing left in liquid solution is
lithium and H2O. To make lithium a solid insert phosphate to the solution (Welcome to Professor
Meyer). It will then turn lithium into lithium phosphate, a solid. Now take the last solid out of
the liquid solution and place it into a separate test leaving water in the test tube, by doing this, all
the metals have been successfully separated and identified as a metal ion. There are some very
basic safety rules that should be followed for this procedure. The first being, wearing appropriate
clothing; closed toed shoes, a full body apron, and goggles, the second is following the procedure
step by step, one wrong move and something could go wrong. That is about it for the safety
rules. Next is the disposal. Metals should not be dumped down a drain. Dispose of them in a
proper waste area. This is the procedure on how to separate and identify the metal ions of cobalt,
lead, lithium, and nickel (See Appendix F).
Even though it is part of the earth’s crust that is not cobalt’s only uses and characteristics.
Cobalt is used in industries, for medical reasons, and in art. Anyways, without it, the color blue
would not exist.
Works Cited
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Bentor, Yinon. "Chemical Elements.com - Cobalt (Co)." Chemical Elements.com - An
Interactive Periodic Table of the Elements. Web. 17 Dec. 2010.
<http://www.chemicalelements.com/elements/co.html>.
Brindley, Lewis. "Aspirin-cobalt Complex Shows Anti-tumour Promise." Royal Society of
Chemistry, the Largest Organisation in Europe for Advancing the Chemical Sciences. 16
Jan. 2009. Web. 17 Dec. 2010.
<http://www.rsc.org/chemistryworld/News/2009/January/16010901.asp>.
"Characterization of Thin-Film Rechargeable Lithium Batteries with Lithium Cobalt Oxide
Cathodes." Scitation. Oct. 1996. Web. 16 Dec. 2010. <http://scitation.aip.org/>
"Chemical Properties and Reaction Tendencies." Cary Academy Homepage. Web. 16 Dec. 2010.
<http://web1.caryacademy.org/chemistry/rushin/StudentProjects/ElementWebSites/cobalt
/Chemical Properties.htm>.
"Cobalt, Chemical Element - Overview, Discovery and Naming, Physical Properties, Chemical
Properties, Occurrence in Nature, Isotopes." Chemistry: Foundations and Applications.
2010. Web. 15 Dec. 2010. <http://www.chemistryexplained.com/elements/AC/Cobalt.html>.
"Cobalt Facts - Periodic Table of the Elements." Chemistry - Periodic Table, Chemistry Projects,
and Chemistry Homework Help. Web. 16 Dec. 2010.
<http://chemistry.about.com/od/elementfacts/a/cobalt.htm>.
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<http://www.chemicool.com/elements/cobalt.html>.
"Cobalt Processing :: Important Cobalt Compounds -- Britannica Online Encyclopedia."
Encyclopedia - Britannica Online Encyclopedia. 2010. Web. 15 Dec. 2010.
<http://www.britannica.com/>.
"Elements - Cobalt (Co) - Chemistry Homework Tutoring." Elements, Chemicals and Chemistry
- Chemistry Homework Tutoring. Web. 17 Dec. 2010.
<http://www.chemicalaid.com/element.php?symbol=Co>.
Everett. "Cobalt." 16 Dec. 2010. Web. 17 Dec. 2010. <http://www.mrteverett.com/>.
Hillman, B., K. D. Bardhan, and J. Bain. "The Use of Dicobalt Edetate (Kelocyanor) in Cyanide
Poisoning -- Hillman Et Al. 50 (581): 171 -- Postgraduate Medical Journal."
Postgraduate Medical Journal - BMJ Journals. Web. 16 Dec. 2010.
<http://pmj.bmj.com/content/50/581/171.abstract>.
Montgomery, Michael. "Cobalt Mine in Congo Featured in Wiki-Leak’s Cables - International
Business Times." IBTIMES.com: International Business News, Financial News, Market
News, Politics, Forex, Commodities - International Business Times. 9 Dec. 2010. Web.
17 Dec. 2010. <http://hken.ibtimes.com/articles/90437/20101209/.htm>.
Rowan, Lisa. "What Are the Uses of Cobalt? | EHow.com." EHow | How To Do Just About
Everything! | How To Videos & Articles. Web. 17 Dec. 2010.
<http://www.ehow.com/about_5105784_uses-cobalt.html>.
"Solubility Chart." Silver Nitrate - Silver Chloride - Gold Chloride - Home. Web. 17 Dec. 2010.
<http://www.saltlakemetals.com/Solubility_Chart.htm>.
Stwertka, Albert. "Cobalt." A Guide to the Elements. New York: Oxford UP, 1996. 92-93. Print.
Welcome to Professor Meyer. Web. 17 Dec. 2010. <http://www.professormeyer.com/>.
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Web. 16 Dec. 2010. <http://www.webelements.com/cobalt/chemistry.html>.
Appendix A
("Cobalt | Chemical Reaction Data.")
Appendix B
(Bentor)
Appendix C
("Elements - Cobalt (Co)”)
Appendix D
Nuclide Mass
Half-Life
Nuclear Spin
Binding Energy
5.43327523969374E-11 J =
47
Co
47.01149(54)#
7/2-#
32719953877.5319 kJ/mol
5.71194327041297E-11 J =
48
Co
48.00176(43)#
6+#
34398132270.8632 kJ/mol
6.02046075812834E-11 J =
49
Co
48.98972(28)#
<35 ns
7/2-#
36256068326.5798 kJ/mol
6.26927933185121E-11 J =
50
Co
49.98154(18)#
44(4) ms
(6+)
37754489057.5244 kJ/mol
6.5628720910684E-11 J =
51
Co
50.97072(16)#
60# ms [>200 ns]
7/2-#
39522546282.0477 kJ/mol
6.7967659362932E-11 J =
52
Co
51.96359(7)#
115(23) ms
(6+)
40931088181.7997 kJ/mol
7.06050923851435E-11 J =
53
Co
52.954219(19)
242(8) ms
7/2-#
42519387743.9383 kJ/mol
7.27947835524107E-11 J =
54
Co
53.9484596(8)
193.28(7) ms
0+
43838050812.4977 kJ/mol
7.51337220046586E-11 J =
55
Co
54.9419990(8)
17.53(3) h
7/245246592712.2497 kJ/mol
7.67264240320018E-11 J =
56
Co
55.9398393(23)
77.233(27) d
4+
46205740456.0378 kJ/mol
7.84683733443247E-11 J =
57
Co
56.9362914(8)
271.74(6) d
7/247254767031.018 kJ/mol
7.99118280866882E-11 J =
58
Co
57.9357528(13)
70.86(6) d
2+
48124035943.6141 kJ/mol
8.15045301140314E-11 J =
59
Co
58.9331950(7)
STABLE
7/249083183687.4022 kJ/mol
8.2798737571412E-11 J =
60
Co
59.9338171(7)
5.2713(8) a
5+
49862573768.8043 kJ/mol
8.42421923137734E-11 J =
61
Co
60.9324758(10)
1.650(5) h
7/250731842681.3992 kJ/mol
8.52379052011926E-11 J =
62
Co
61.934051(21)
1.50(4) min
2+
51331475100.416 kJ/mol
8.66813599435561E-11 J =
63
Co
62.933612(21)
26.9(4) s
7/252200744013.0121 kJ/mol
8.76770728309742E-11 J =
64
Co
63.935810(21)
0.30(3) s
1+
52800376432.0283 kJ/mol
8.88220330033731E-11 J =
65
Co
64.936478(14)
1.20(6) s
(7/2)53489887682.2372 kJ/mol
8.96684986058125E-11 J =
66
Co
65.93976(27)
0.18(1) s
(3+)
53999641270.062 kJ/mol
9.08134587782114E-11 J =
67
Co
66.94089(34)
0.425(20) s
(7/2-)#
54689152520.2709 kJ/mol
9.15106770956701E-11 J =
68
Co
67.94487(34)
0.199(21) s
(7-)
55109027276.9031 kJ/mol
9.25063899830883E-11 J =
69
Co
68.94632(36)
227(13) ms
7/2-#
55708659695.9193 kJ/mol
9.30543610155641E-11 J =
70
Co
69.9510(9)
119(6) ms
(6-)
56038655621.3576 kJ/mol
9.4199321187963E-11 J =
71
Co
70.9529(9)
97(2) ms
7/2-#
56728166871.5665 kJ/mol
9.47472922204389E-11 J =
72
Co
71.95781(64)#
62(3) ms
(6-,7-)
57058162797.0047 kJ/mol
9.55937578228784E-11 J =
73
Co
72.96024(75)#
41(4) ms
7/2-#
57567916384.8295 kJ/mol
9.61417288553522E-11 J =
74
Co
73.96538(86)#
50# ms [>300 ns]
0+
57897912310.2665 kJ/mol
9.69881944577896E-11 J =
75
Co
74.96833(86)#
40# ms [>300 ns]
7/2-#
58407665898.0901 kJ/mol
(Everett)
Appendix E
(Welcome to Professor Meyer.)
Appendix F