Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms

Autor/in	Buth, Jeffrey M.
Titel	Ocean Acidification: Investigation and Presentation of the Effects of Elevated Carbon Dioxide Levels on Seawater Chemistry and Calcareous Organisms
Quelle	In: Journal of Chemical Education, 93 (2016) 4, S.718-721 (4 Seiten)Infoseite zur Zeitschrift PDF als Volltext Verfügbarkeit
Sprache	englisch
Dokumenttyp	gedruckt; online; Zeitschriftenaufsatz
ISSN	0021-9584
DOI	10.1021/acs.jchemed.5b00676
Schlagwörter	Leitfaden; Unterricht; Lehrer; Chemistry; Science Instruction; College Science; Undergraduate Study; Environmental Education; Science Laboratories; Oceanography; Water; Laboratory Experiments; Science Experiments; Scientific Concepts; Ecology; Ohio + Suchen Sie Ihr Suchwort? Lesson concept; Instruction; Unterrichtsentwurf; Unterrichtsprozess; Teacher; Teachers; Lehrerin; Lehrende; Chemie; Teaching of science; Science education; Natural sciences Lessons; Naturwissenschaftlicher Unterricht; Grundstudium; Umweltbildung; Umwelterziehung; Umweltpädagogik; Ozeanografie; Wasser; Laboratory work; Laborarbeit; Ökologie
Abstract	Ocean acidification refers to the process by which seawater absorbs carbon dioxide from the atmosphere, producing aqueous carbonic acid. Acidic conditions increase the solubility of calcium carbonate, threatening corals and other calcareous organisms that depend on it for protective structures. The global nature of ocean acidification and the magnitude of its potential impact on marine ecosystems and the industries they support make it an important and engaging topic to explore in the undergraduate laboratory. In this multiweek experiment, designed for second year analytical and environmental chemistry courses, artificial seawater samples containing pieces of seashell or coral were prepared. One sample was pressurized with carbon dioxide and stirred for 1 week, while the other was stirred without carbonation. Mass and pH measurements and carbonate, bicarbonate, calcium(II), and magnesium(II) titrations were performed on samples before and after treatment. Through data analysis and a rigorous consideration of the acid-base and solubility equilibria involved, students concluded that carbonation significantly decreased seawater pH and caused appreciable seashell and coral dissolution, which raised the bicarbonate and calcium(II) concentrations. Minimal change in the seawater chemistry or carbonaceous material was observed for the noncarbonated sample. Overall, the experience provided a meaningful experimental context for titration analyses and a practical application of the conceptual treatment of a multiequilibrium system. In addition to the experiment, a corresponding oral presentation assignment is presented, in which students produced a video designed to educate a general audience on the topic of ocean acidification by using their experimental results as support. Through this assignment, students reflected on the broader ecological and societal ramifications of ocean acidification and developed the ability to communicate scientific knowledge to a nonscientific audience, a critical collaborative skill for addressing such multifaceted issues. (As Provided).
Anmerkungen	Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
Erfasst von	ERIC (Education Resources Information Center), Washington, DC
Update	2020/1/01