CHEM 2121 Lecture Notes - Analyte, Ringfort, Pro 2
Document Summary
Energy increases right --> left, wavelength does opposite. Ir: induces vibration; -->can be used for qualitative work since different molecules need different amounts of work to vibrate the bonds. Uv-vis: promote electrons to higher energy levels; *focusing here. Can promote electron to higher electronic statewith some more energy, can go into a rotational state too; many different ways you can go -->absorbance (a) Need to select certain wavelength to hit our sample. Then the light hits a sample and some of the light comes out. Transmittance (t): measures relatively how much light comes out; what fraction makes it out of the sample; what percentage is transmitted. -t = p/p0 0 <= t <= 1. Think of it as probability: what"s the chance that the molecule"s absorbed? the bigger the circle gets, the more likely to absorbdirect relationship with concentration, area of the particle, and thickness of the particle.
