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ERIC Number: EJ1003056
Record Type: Journal
Publication Date: 2012-Nov
Pages: 3
Abstractor: As Provided
Reference Count: 12
ISSN: ISSN-0021-9584
Experimental Determination of pK[subscript a] Values by Use of NMR Chemical Shifts, Revisited
Gift, Alan D.; Stewart, Sarah M.; Bokashanga, Patrick Kwete
Journal of Chemical Education, v89 n11 p1458-1460 Nov 2012
This laboratory experiment, using proton NMR spectroscopy to determine the dissociation constant for heterocyclic bases, has been modified from a previously described experiment. A solution of a substituted pyridine is prepared using deuterium oxide (D[subscript 2]O) as the solvent. The pH of the solution is adjusted and proton NMR spectra are collected for a variety of pH values. The chemical shifts of the peaks in the NMR spectrum change depending on the degree of protonation of the pyridine ring. Analysis of the spectral data is used to calculate the dissociation constant of the substituted pyridine. This experiment is suitable for a variety of advanced chemistry laboratories including analytical chemistry and instrumental analysis. (Contains 1 table and 2 figures.)
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:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A