Analysis of a complex gaseous mixture using ro-vibrational spectroscopy: A study of the Ira Remsen reaction for the upper-division laboratory
Presentation Type
Poster
Keywords
Copper, nitric acid, infrared absorption cross section, FTIR spectroscopy, vibrational spectroscopy, physical chemistry laboratory, nitrogen oxides
Department
Chemistry
Major
Chemistry, B.S.
Abstract
The dissolution of copper metal in nitric acid, a centuries-old reaction with striking visual appeal, provides a complex gaseous mixture displaying the rich chemistry of nitrogen. We present here a project for the physical/atmospheric chemistry laboratory that utilizes ro-vibrational (FTIR) spectroscopy to investigate the IR-active, nitrogen-containing gases generated by the historic “Ira Remsen” reaction. Effective integrated absorption cross-sections derived from quantitative spectral databases (EPA, PNNL) were employed to determine yields of the gaseous products. These include the atmospherically-relevant gases NO2 (and N2O4), NO, N2O, cis- and trans-HONO, HNO3 and ClNO, arising from chloride contamination. It was demonstrated that NO2 and NO are the dominant gas-phase products using concentrated and dilute nitric acid, respectively, and that N2O is likely formed via the acid-catalyzed hydrolysis of NO2. The experiment provides a familiar context through which to introduce (a) ro-vibrational spectroscopy of several spectroscopic classes of molecules, (b) the quantification of gases in mixtures, and (c) gases involved in tropospheric smog chemistry.
Faculty Mentor
Dr. Jane Ganske
Funding Source or Research Program
Academic Year Undergraduate Research Initiative
Location
Waves Cafeteria
Start Date
23-3-2018 2:00 PM
End Date
23-3-2018 3:30 PM
Analysis of a complex gaseous mixture using ro-vibrational spectroscopy: A study of the Ira Remsen reaction for the upper-division laboratory
Waves Cafeteria
The dissolution of copper metal in nitric acid, a centuries-old reaction with striking visual appeal, provides a complex gaseous mixture displaying the rich chemistry of nitrogen. We present here a project for the physical/atmospheric chemistry laboratory that utilizes ro-vibrational (FTIR) spectroscopy to investigate the IR-active, nitrogen-containing gases generated by the historic “Ira Remsen” reaction. Effective integrated absorption cross-sections derived from quantitative spectral databases (EPA, PNNL) were employed to determine yields of the gaseous products. These include the atmospherically-relevant gases NO2 (and N2O4), NO, N2O, cis- and trans-HONO, HNO3 and ClNO, arising from chloride contamination. It was demonstrated that NO2 and NO are the dominant gas-phase products using concentrated and dilute nitric acid, respectively, and that N2O is likely formed via the acid-catalyzed hydrolysis of NO2. The experiment provides a familiar context through which to introduce (a) ro-vibrational spectroscopy of several spectroscopic classes of molecules, (b) the quantification of gases in mixtures, and (c) gases involved in tropospheric smog chemistry.