Exploring Color: Introduction to Spectroscopy
Hand-In, Chem 150L, Fall 2015
Name:
Partner:
See the attached rubric for more detailed information about grading.
1. (3 points) 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. (3 points) For each single-colored solution (red, yellow, blue) use the information in the table above to explain the
relationship between the observed colors and the wavelengths of maximum absorbance and maximum transmittance.
Red:
Yellow:
Blue:
3. (3 points) For the mixed-colored solutions (orange, green, purple), use the information in the table above to explain
the relationship between the observed colors and the wavelengths of maximum absorbance and maximum
transmittance.
Orange:
Green:
Purple:
4. (5 points) Attach the graph you prepared of Absorbance vs. Concentration for the three wavelengths of one of the
colored solutions and explain any trends you see in your graphs. How is the absorbance of a solution related to the
concentration of the solution? After identifying the relationship explain it by discussing the interaction of photons of
light with solute particles.
{Paste graph here}
{Type answer here}
5. (2 points) Why do colored solutions appear to be colored?
{Type answer here}
6. (4 points) Attach the Absorbance vs. Wavelength spectra for both of the samples you brought in to lab. Explain these
spectra. Make sure you specify what each sample was and describe in detail why each sample has the observed color
that it does.
{Paste spectra here}
{Type answer here}
See the attached rubric for more detailed information about grading.
Unsatisfactory
Borderline
Q#1
Ranges
and
colors
0 points
1 point
Satisfactory
-0.5 pts for each
error identifying the
color of particular
wavelength ranges.
2 points
Q#2
Explanation of
primary
colors
0 points
Q#3
Explanation of
mixtures
Q#4
Abs vs.
Conc
0 points
No graph, no
points
1 point
0-1 point
2 points
Vague or
poorly
expressed
explanation
1 point
Q#5
Why
colors?
Q#6
Explanation of
own
samples
1 point
Explanation
not logical.
0 points
No spectra, no
points.
No explanation,
no points.
0 points
2 points
Minor flaws in
reasoning.
2 points
3-4 points
Excellent
Reasonable ranges are given
and colors are properly
identified.
3 points
+2 pts for relationship
between observed color and
wavelength of absorbed light.
+1 pt for rel. between
observed color and
wavelength of transmitted
light.
3 points
Reasonable discussion of why
the mixture has the observed
color it does based on
wavelength of absorbed
and/or transmitted light.
3 points
Proper graph formatting 2pts
Identify trend in data 1pt
Explain trend in data 2 pts
5 points
Reasonable and clearly
expressed explanation
Pts.
3 pts
3 pts
3 pts
5 pts
2 pts
2 points
Same criteria as Q#2&3 2pts
for each solution
4 pts
1-2 points
3 points
4 points
20 pts