CHEM 110 Lecture Notes - Lecture 21: Electromagnetic Spectrum, Boltzmann Constant, Spectroscopy
Monday, October 23, 2017
Spectroscopy
CHEM 110
-Butler is interested in Art Forensics
-Spectroscopy:
•When matter interacts with or emits electromagnetic radiation
•Graphs
-Vibrations of the molecule denoted by drop spikes in graph
-Big Bands around 3000 = C-H bonds
-“Fingerprint region” - each molecule has a unique spectrum
•we can use this to identify bonds
-checking olympic drug use: they check electromagnetic spectrum!
•Infrared: Net change in the dipole moment derivative during the vibration
•Raman: Net change in the polarizability derivative during the vibration
-Q = normal coordinate (normal vibration)
-Carbon monoxide has a poor bond, therefore does have IR
•You can distinguish between synthetic stuff or real stuff too
•Raman
-studied effects of light (sunlight)
-change in the polarizability in that vibration
•k = boltzmann constant
•Radiant scattering —> why we have a blue sky
•Raman measurements:
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-IR
•IR absorption leads to sample heating and the heat is transferred to the helium gas
•Pigments emit sounds…?
•PAIR Spectroscopy
•Desiccant = drying agent (methanol?)
•Art Conservation = capacity to restore
•Pigments:
-Inorganic and organic (plants and insects)
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CHEM 110 Full Course Notes
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Document Summary
Spectroscopy: when matter interacts with or emits electromagnetic radiation, graphs. Vibrations of the molecule denoted by drop spikes in graph. Big bands around 3000 = c-h bonds. Fingerprint region - each molecule has a unique spectrum: we can use this to identify bonds. Checking olympic drug use: they check electromagnetic spectrum: infrared: net change in the dipole moment derivative during the vibration, raman: net change in the polarizability derivative during the vibration. Carbon monoxide has a poor bond, therefore does have ir: you can distinguish between synthetic stuff or real stuff too, raman. Change in the polarizability in that vibration: k = boltzmann constant, radiant scattering > why we have a blue sky, raman measurements: Ir: ir absorption leads to sample heating and the heat is transferred to the helium gas, pigments emit sounds , pair spectroscopy, desiccant = drying agent (methanol?, art conservation = capacity to restore, pigments:
