1. Spectrophotometry (A type of Spectroscopy)
The quantitative measurement of the reflection or transmission properties of a material as a function of the wavelength of light upon which it is impinged.
IR Spectroscopy:
Vibrates molecules--Used to identify bond types.
Visible Light/ UV Spectroscopy:
Creates electron transitions—Used to determine concentrations of absorbing molecules.

2. Complimentary Color Wheel

3. A = a b C Ameas = k Cknown A = k C Ameas = kknown C Beer’s Law
Absorbance= -log transmittance
I = intensity of the light
Zero Adjust/ 100% Transmittance Button
◄(I/I0 = 1)
Sample Chamber
Wavelength Adjustment Knob
A = a b C
Ameas = k Cknown
A = k C
Ameas = kknown C
Beer’s Law

5. l n = c
E = hn
E = hc/l
Absorption Spectrum of Cu(H2O)62+

6. Given the following data for a series of containing copper (II) ion solutions, construct a graph of absorbance vs. concentration and determine the slope of the best fit line to find the Beer’s Law constant.
Conc. of the copper ion % Transmittance
Absorbance
0.314
0.242
0.185
0.120
0.052
Use Beer’s Law to determine the concentration of an unknown sample with an absorbance of
k = 6.46
0.215 = (6.46) C
0.033 M = C

8. Absorption Spectrum for FeSCN2+

9. 1. Find the number of moles of each reactant.
2. Find the number of moles of product formed.
3. Find the number of moles of reactant at eq.
4. Find the concentration of all species at eq.
5. Find the value of Kc for the reaction.