Exploring Color: Introduction to spectroscopy
Hand-In, Chem 150L, Spring 2013
Name:
Partner:
Circle or highlight your lab assistant/room/time:
Kaila
Ashley
SL302
SL306
1. For colored solutions measured in the first part of the experiment:
Observed
Color:
Wavelength Range(s)
of Maximum
Absorbance
Color(s) of Light
Corresponding to the
Wavelength Range(s) of
Maximum Absorbance
Wavelength Range(s)
of Minimum
Absorbance (Maximum
Transmittance)
Color(s) of Light
Corresponding to the
Wavelength Range(s) of
Minimum Absorbance
(Maximum Transmittance)
Red
Orange
Yellow
Green
Blue
Purple
2. For the single-colored solutions (red, yellow, blue), explain the relationship between the wavelength
range(s) of the observed colors and the wavelength range(s) of maximum absorbance and transmittance
listed in question #1.

3. For the mixed-colored solutions (orange, green, purple), explain the relationship between the wavelength
range(s) of the observed colors and the wavelength range(s) of maximum absorbance and transmittance
listed in question #1.

4. How is the absorbance of a solution related to the concentration of the solution? Explain this observation,
paying particular attention to the interaction of photons with solute particles. Include the graph(s) you
prepared of Absorbance vs. Concentration and explain any trends you see in your graphs.

5. Why do colored solutions appear to be colored?

6. Explain the Absorbance vs Wavelength spectra for the 2 samples you used in the lab. Make sure you specify
what each sample was and describe in detail how the spectrum you measured results in the observed color of
each sample. Include the spectra for both samples.

7. In preparation for writing full lab reports, write a “Conclusions” section for this experiment. The
“Conclusions” section should include a summary of the results of the experiment and a “big picture” context
of those results. Was the purpose of the experiment addressed in your data and analysis? What key
information/concepts will you take from this experiment?