Temperature and electric field dependence of asymmetric stretching of nitrate ion
Grade Level at Time of Presentation
Senior
Major
Chemistry
Minor
Physics and mathematics
Institution
Western Kentucky University
KY House District #
20
KY Senate District #
32
Faculty Advisor/ Mentor
Matthew J. Nee, PhD
Department
Chemistry
Abstract
The decomposition of ubiquitous nitrate ion by exposure to sunlight (photolysis) produces toxic gases such as nitrogen monoxide, nitrogen dioxide, and ozone, which are harmful to human health and the atmosphere. Different induced nitrate geometries in water environments may contribute differently to the amount of products that form during photolysis. To better understand the steps of nitrate photolysis, the effects of different concentrations of charged particles (ions) in solution on nitrate geometry distortion is needed. Infrared light was used to measure the different molecular distortions of nitrate ion at a series of specified constant temperatures with varying amounts of total ions in solution. The different charged particles (arising from water molecules and other ions in solution) in solution of nitrate ion distort the geometry of the nitrate ion. Computational energy maps are generated with different nitrate geometries to better understand nitrate ion distortions. Different molecular motions are observable in the experimental graph of the energies of different motions of nitrate ions dissolved in water. The difference in energy between the two geometries is determined to be linearly proportional to the number of ions in the solution. As number of ions increases, the lower energy geometries becomes more favored. A specific initial path may be favored in low salt concentrations, leading to different products (such as more ozone, or more nitrogen monoxide) when exposed to light. Thus, the ratio of the nitrate geometries in water can be correlated to the amount of each product produced during photolysis to help explain the ionic strength dependence of the yields of those products.
Temperature and electric field dependence of asymmetric stretching of nitrate ion
The decomposition of ubiquitous nitrate ion by exposure to sunlight (photolysis) produces toxic gases such as nitrogen monoxide, nitrogen dioxide, and ozone, which are harmful to human health and the atmosphere. Different induced nitrate geometries in water environments may contribute differently to the amount of products that form during photolysis. To better understand the steps of nitrate photolysis, the effects of different concentrations of charged particles (ions) in solution on nitrate geometry distortion is needed. Infrared light was used to measure the different molecular distortions of nitrate ion at a series of specified constant temperatures with varying amounts of total ions in solution. The different charged particles (arising from water molecules and other ions in solution) in solution of nitrate ion distort the geometry of the nitrate ion. Computational energy maps are generated with different nitrate geometries to better understand nitrate ion distortions. Different molecular motions are observable in the experimental graph of the energies of different motions of nitrate ions dissolved in water. The difference in energy between the two geometries is determined to be linearly proportional to the number of ions in the solution. As number of ions increases, the lower energy geometries becomes more favored. A specific initial path may be favored in low salt concentrations, leading to different products (such as more ozone, or more nitrogen monoxide) when exposed to light. Thus, the ratio of the nitrate geometries in water can be correlated to the amount of each product produced during photolysis to help explain the ionic strength dependence of the yields of those products.