PRELIM 03 - Spectroscopy Flashcards
Refers to measurements based on the interactions between light and other forms of electromagnetic radiation and matter
Spectroscopy
Form of energy that is transmitted through space at enormous velocities
Electromagnetic radiation
The highest part of a wave (Parts of a wave)
Peak
Distance between two peaks/troughs (Parts of a wave)
Wavelength
The lowest part of a wave (Parts of a wave)
Trough
The vertical distance between the crest/trough and the midline (Parts of a wave)
Amplitude
4 properties of a wave (WFVA)
Wavelength, Frequency, Velocity, Amplitude
Are spectroscopic methods that are based on ultraviolet, visible, and infrared radiation
Optical methods
UV region (Wavelength range)
180-380 nm
Visible region (Wavelength range)
380-780 nm
Near-IR (Wavelength range)
0.78-2.5 μm
Mid-IR (Wavelength range)
2.5-5.0 μm
Measurements that use the interaction of radiation with matter to obtain information about sample
Spectroscopic measurements
Prior to applying the stimulus, the analyte is predominantly in its lowest energy (Types of energy state)
Ground state
The stimulus then causes some of the analyte species to undergo a transition to a higher energy (Types of energy state)
Excited state
Method in which the stimulus is heat or electrical energy (Spectroscopic measurements based on stimulus)
Emission spectroscopy
Method that involves the excitation of analyte by a chemical reaction (Spectroscopic measurements based on stimulus)
Chemiluminescence spectroscopy
The incident radiation (Po) can be absorbed and promote some of the analyte species to an excited state, resulting in a transmitted beam of lower radiant power (P) (Spectroscopic measurements based on radiation)
Absorption spectroscopy
Results on the absorption of electromagnetic radiation and then dissipation of the energy by emission of radiation; emission occurs over all angles (Spectroscopic methods based on radiation)
Photoluminescence spectroscopy
Refers to the radiant power in watts that incidents on sample (output light)
Incident radiant power (Po)
Refers to the radiant power transmitted by sample (input light)
Transmitted radiant power (P)
Is related to the transmittance in a logarithmic manner
Absorbance (A)
Refers to the fraction of incident radiation transmitted by the solution
Transmittance (T)
Refers to the length over which attenuation occurs
Path length of sample
Unit of molar concentration
Molarity (M)
Standard path length used when there is no given
1 cm
Law that states the relationship between the attenuation of light through a substance and the properties of that substance
Beer-Lambert’s law
