Paramagnetism Paradoxes: Projectable Demonstrations

Ed Vitz
Department of Chemistry, Kutztown University, Kutztown, PA 19530
Frederick C. Sauls
Department of Chemistry and Physics, King''s College, Wilkes-Barre, PA 18711
Charles Malerich
Department of Natural Sciences and Chemistry, Baruch College, New York, NY 10010
J. Chem. Educ., 2008, 85 (4), p 529
DOI: 10.1021/ed085p529
Publication Date (Web): April 1, 2008

Abstract

Drops of oil in Mn(SO4)(aq) and drops of the solution in oil show opposite effects when brought near a rare earth magnet. Oxygen, nitrogen, and air bubbles atop water show expected attraction, repulsion, and null behavior, respectively. Air bubbles atop aqueous Mn(SO4) show paradoxical behavior because the magnet's attraction of the solution forms a complex crest. The existence and shape of this crest is examined, and the unexpected behavior used to motivate student examination of paramagnetism. Several improvements in the bubble demonstration are suggested. A rare earth magnet is also powerful enough to demonstrate paramagnetism in crystals of Fe2(SO4)3·9H2O, FeSO4·7H2O, CoCl2·6H2O, MnSO4·H2O, and to a lesser extent CuSO4·5H2O, CuCl2·2H2O, NiCl2·6H2O, MnO2, and NiSO4·7H2O.

Keywords (Audience):

First-Year Undergraduate / General

Keywords (Domain):

Demonstrations

Keywords (Feature):

JCE DigiDemos: Tested Demonstrations

Keywords (Pedagogy):

Misconceptions / Discrepant Events

Keywords (Subject):

Magnetic Properties
View: Hi-Res PDF | PDF w/ Links

Tools

SciFinder Links

SciFinder subscribers: Click to sign in | Not a SciFinder subscriber? Learn more at www.cas.org

Explore by:

History

  • Received: August 03, 2009

Recommend & Share

  • Share on ACS NetworkACS Network
  • Add to FacebookFacebook
  • Tweet ThisTweet This
  • Add to CiteULikeCiteULike
  • Add to NewsvineNewsvine
  • Digg ThisDigg This
  • Add to DeliciousDelicious

Related Content