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ERIC Number: EJ828688
Record Type: Journal
Publication Date: 2009-Feb
Pages: 3
Abstractor: As Provided
Reference Count: 10
ISSN: ISSN-0021-9584
Revisiting History: Encountering Iodine Then and Now--A General Chemistry Laboratory to Observe Iodine from Seaweed
Wahab, M. Farooq
Journal of Chemical Education, v86 n2 p206-208 Feb 2009
The history of the discovery of iodine is retold using brown-colored seaweed found commonly along the ocean shore. The seaweed is ashed at a low temperature and the iodides are extracted into boiling water. The iodides are oxidized in acidic medium. Solvent extraction of iodine by oxidation of iodides as well as simple aqueous extraction of iodide salts is done. Slight warming of the solution produces discernible violet vapors in an Erlenmeyer flask when seen against a white background. The origin of iodine's name--discussed in the article--is proven in the laboratory experiment. More generally, this activity serves to increase students' interest in analytical chemistry, as well as relationships among elements in the periodic table. (Contains 2 figures.)
Division of Chemical Education of the American Chemical Society. Subscription Department, P.O. Box 1267, Bellmawr, NJ 08099-1267. Tel: 800-691-9846; Tel: 856-931-5825; Fax: 856-931-4115; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Location: Pakistan