edited by E. K. MELLDN Florida State University Tallahassee,FL 32306
reactivity network Reactivity of Nickel James P. Birk and Matiha Ronan Arizona State University. Tempe, AZ 85287 Imogene Bennett Chaparral High School, Scottsdale, AZ 85253
Cheri Kinney Marcos de Nlza High School, Tempe, AZ 85282 Nickel is a hard. silverv white metal that is ouite ductile and malleable, mhderatily strong and tough, iesistant to corrosion. and caoahle of takinr! a hieh .. .volish. Because of these properties it is often used to plate other metals or as a comDonent of allow to which it imparts toughness. Nickel is ferromagnetic (his a permanent magnetism like iron and cobalt) and is used in many permanent magnets. The density of nickel is 8.908g/cm3 (I),its meltingpoint is 1453 "C ( I ) , and its boiling point is 2732 "C (I). T h e thermalconductivity is 90.90 J/m s deg (I), while the electrical conductivity is 146.2 (mohm cm)-l ( I ) . Nickel is not a particularly good conductor of heat or electricitv: these values are comoarable to those of tungsten (173.00~Jlms deg and 177.0 imohm cm)-') (I),which is usedas a heating element in toasters and light bulbs. In contrast, the values for copper, a good conductor, are 401.00 J l m s deg and 595.8 (mohm cm)-' ( I ) . T h e 1989 cost of pure nickel is $2.60/100 g and the cost of bulk nickel is $0.361100 g (I).
Bunsen burner flame. Caution: The nickel and the magnet will be quite hot. After a few minutes, the nickel will lose its ferromagnetism and fall off the magnet, Immediately try to pick it up with the magnet. As the nickel cools, it will regain its ferromagnetism,and it will be possible to pick it up with the magnet again. Useappropriate precautions to prevent skin burns. Abundance and Occurrence of Nlckel Nickel is 24th in abundance among the elements, occurring in the earth's crust to the extent of about 0.016%. It is a common constituent of iron meteorites, which usually contain 5 4 0 % nickel. About 10% of the earth's core consists of nickel. Nickel was first isolated in 1751 in impure form by Axel F. Cronstedt, a Swedish chemist (3).He prepared nickel metal from an ore containing niccolite (NiAs). Ores of this t w e had oroved troublesome to coooer and silver miners in the Harz ~ o u n t a i n in s Germany since they resembled copper in color, but yielded an unfamiliar brittle product when
Experiment 1: Magnetism of Nickel The ferromagnetism of nickel can be observed by touching apiece of nickel with a magnet. The nickel will adhere to the magnet. If no other source of nickel is available, a Canadian five-cent piece is made of pure nickel. A US. five-centcoin is only about 25% nickel and will not work in this experiment. The ferromagnetism of nickel (and iron and cobalt)will disappear if the metal is heated sufficiently. The metal then becomes merely paramagnetic and is no longer strongly attracted to a magnet. The temperature at which a ferromagnetic substance is converted to a paramagnetic substance is called the Curie point, which is 358 'C for nickel (2),easily within the range of a Bunsen burner flame. Pick up a nickel piece with a magnet, and hold the nickel in a
About the Edltor
Introduction to Reactlvlty Network
I 48
The systematic study of inorganic chemical reactivity in underrepresentedinthe high School chemistry c~rric~lum. It isa Shamethatthis is the case, since many of the phenomena represented in this field are impressive to observe and inherently interesting to a greater degree than many of the mare theoretical topics currently offered. The purwses of the Reactivitv Network. cansistina of some 200 chemical educators,are toextract informationaboutinorganic chemical reactivity from the chemical literature, to package the informetionas iaboratory exercises and problems, and to disseminate ttm information to high school teachers, textboak authors, and cuniculum developers. The following paper on nickel chemistry by Jim Birk, Marlha Ransn, Imogene Bennett, and Cheri Kenney represents such an effort by a Reactivily Network writing team consisting of an Inorganic chemist and three ex~erienoedhigh schml teachers.
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Journal of Chemical Education
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E. K. Mollon was educated at the University ofTexas (Austin:BS and and taught at St. Edwards University. He was e Postdoctoral
PhDl
Fellow end Lecturer at the University of Michigan (Ann Arbor). Since 1966. he has bean a member of Me chemistry faculty at the Florida State University, where he is Chairman of the Chemisby Department and Professor. Awards include the Florida Award (Florida Section. ACS), the Visiting Scientist Award (Western Connecticut Section. ACS), a CMA National Catalyst Award, and teaching awards at Flwida state.
processed. The miners blamed the devil and called this material "hu~fernichel",meaning Old Nick's (or Satan's) copper. Due &similar properties such as atomic and ionic radii, density, melting point, and boiling point, the successive members of the transition metal series, Fe, Co, Ni, and Cu, show considerable resemblance to one another. For this reason, nickel is often found associated with ores of these other metals. For example, the primary ore found in Ontario, which nrovides much of the world's s u n ~ l of v nickel. is Dentlandite', a mixed sulfide of iron and nGkei: (Ni, ~ e ) & . ~ ~ h i s region also produces pyrrhotite, an iron ore (Fe& to FelsS17) that often contains nickel impurities. Nickel impurities are also often associated with copper ores such as chalcopyrite, CuFeSn. Other deposits of ni'ckel ores that occur in sufficient quantity, concentration, and accessibility for commercial d&elop&ent are found in New Caledonia, Australia, Cuba, and Indonesia. Experiment 2: Chromatographic Separation of Nickel One way that nickel can be separated from other metals involves ehromatoeraohv. " . . While this method is not used on an industrial scale to process nickel ores, it is useful on a smaller scale for the separation and analysis of nickel solutions. In column chromatographys vertical glass column is packed with a suspension of an appropriate adsorbent in a solvent. The mixture to be~separatedisdissdved in a minimum volume oian appropriatr solvent, added to [he top of the column, and allowed t o seep YII)WIY into the adsorbent. A suitable advent is then pasred through the column, causing separation of the components. Some common adaorhents are silica eel (colloidalsilicon dioxide). alumina (aluminum oridel silicate). . . silicic acid. calcium carbon~ ~florid . . (a .~mamesium ,. ate, and sucrose. The separation otnickel(ll) and nrhslt(1l)on on anion exchange wain has been dwerihed elsewhere (41.Thij experiment demonstrates column chromatography on a small scale and uses capillary action rather than gravity to move the solvent through the column. Fill a melting point tube (sealed at one end) with alumina. Rubbing gently with a file will help to pack the alumina tightly. When filled, place a drop of water on the open end of the tube. allowine the tube to be uo-ended without soilline the contents. ~nref~~llYeu
