19090927
Description
Flashcards by silent voice, updated more than 1 year ago
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Created by silent voice
over 5 years ago
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| Question | Answer |
| SPECTROSCOPY? | The study of the interaction between ELECTROMAGNETIC (EM) RADIATION and MATTER. |
| EM Radiation? | Is a form of energy that has both Wave and Particle properties. e.g: Ultraviolet, visible |
| Wave Properties? (Electric Field) | At 90° to the direction of propagation is an oscillation in the ELECTRIC FIELD. |
| Wave Properties? (Magnetic Field) | At 90° to the direction of propagation and 90° from the electric field oscillation is the MAGNETIC FIELD oscillation. |
| PERIOD (p)? | the time required for one cycle to pass a fixed point in space |
| FREQUENCY (f@v) ? | the number of cycles which pass a fixed point in space per second. Unit in Hz or s-1 |
| AMPLITUDE (A)? | The maximum length of the electric vector in the wave (Maximum height of a wave). |
| WAVELENGTH( lamda)? | The distance between two identical adjacent points in a wave (usually maxima or minima). |
| WAVENUMBER? | The number of waves per cm in units of cm-1 |
| RADIANT POWER (P)? | The amount of energy reaching a given area per second. Unit in watts (W). |
| INTENSITY (I)? | The radiant power per unit solid angle. |
| C=V(lamda) | ? |
| wavelength( lamda) 8 1/frequency(v) | The higher the ν, the shorter the λ |
| Particle Properties (1) | EMR is viewed as a stream of discrete particles of energy called photons. |
| Particle Properties (2) | We can relate the energy, E of photon to its wavelength, frequency and wavenumber |
| ABSORPTION | the measure of the decrease in radiant power. |
| Quantitative absorption methods require 2 power measurements: | 1) Po = incident radiant power 2) P = transmitted radiant power |
| Transmittance (commonly expressed in %) | The fraction of incident radiation transmitted through the sample medium. |
| Absorbance | A measurement of the amount of radiant power absorbed by the sample defined as the -ve log of T. |
| BEER'S LAW | A= abc @ A=Ebc |
| Limitations to The Applicability of Beer’s Law (3) | i.Fundamental ii. Instrumental iii. Chemical deviations |
| FUNDAMENTAL DEVIATION | CAUSING DEVIATION FROM THE LINEAR RELATIONSHIP BTW ABSORBANCE AND CONCENTRATION |
| INSTRUMENTAL DEVIATION | DUE TO POLYCHROMATIC DEVIATION DUE TO THE PRESENCE OF STRAY RADIATION |
| CHEMICAL DEVIATION | Occur when the analyte undergo dissociation, association or reaction with the solvent to give products that absorb differently than the analyte. |
| ABSORPTION | EMR energy transferred to absorbing molecule (transition from low energy to high energy state). |
| EMISSION | EMR energy transferred from emitting molecule to space (transition from high energy to low energy state). |
| SCATTERING | Redirection of light with no energy transfer. |
| a molecule may absorb energy in 3 ways: | 1. By raising an electron (or electrons) to a higher energy level. (electronic) 2.By increasing the vibration of the constituent nuclei. (vibrational) 3.By increasing the rotation of the molecule about the axis. (rotational) |
| Absorption spectrum | a series of sharp, well-defined peaks caused by excitation of individual atoms. |
| Band spectrum | several groups of lines so closely spaced that they are not completely resolved. |
| Continuum spectrum | a beam of light that contains a broad, smooth distribution of photon wavelength. |
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