Introduction |
| Anchor Video |
| Concept Map |
| Project Calendar |
| Lesson Plans |
| Letter to Parents |
| Assessments |
| Resources |
| Modifications |
| Grant |
Resource List
Biology
Chemistry
Statistics
Biology
1.
Carbon Cycle-
http://www.epa.gov/globalwarming/kids/carbon_cycle_version2.html
2. What is Happening-
Classroom
Resources
1.
Carbon Cycle-
2
medium sized
plants (about 1ft tall)
2
large glass
jars
small
amount
of soda lime crystals
45
test tubes
15
limestone
rock
Few
seashells
Small
bag of
soil
2.
Greenhouse Effect-
baking
soda
bottle
of
vinegar
Plastic
Wrap
(saran)
10 computers
LogPro Software
10 Temperature
Probes
10 heat lamps
10 100 W bulbs
40 600 mL beakers
3. Nitrogen Cycle-
Biovue animation from Prentice Hall Biology
4. What is Happening-
Computers with internet access
Chemistry
Web Resources:
- Environmental Chemistry Content:
- environmentalchemistry.com
i.
http://environmentalchemistry.com/yogi/environmental/200611CO2globalwarming.html
ii.
http://environmentalchemistry.com/yogi/chemistry/200609fluorine.html
iii.
http://environmentalchemistry.com/yogi/environmental/200608hydrogenfuelcells.html
- Spectroscopy:
- Basic Information:
i.
http://en.wikipedia.org/wiki/Spectroscopy
ii.
http://speclab.cr.usgs.gov/
iii.
http://www.scienceofspectroscopy.info/
- Lesson Plans
- Environmental Chemist:
i.
Manufacturing
in the Age of Recycling
1.
http://www.sme.org/memb/neweek/actrec.htm
ii.
Air Junk, Specks,
Flecks and Particles in the Air
1.
http://www.hhmi.org/coolscience/airjunk/nosep2.html
iii.
Bringing
The Greenhouse Effect Down To Earth
1.
http://www.fi.edu/tfi/activity/earth/earth-4.html
iv.
Sorting out Science
from Junk Science
1.
http://environmentalchemistry.com/yogi/environmental/200608junkscience.html
v.
Effects of Air
Pollution on our Health
1.
http://environmentalchemistry.com/yogi/environmental/200602airpollution.html
vi.
Environmental Chemists
b.Chemistry
of Cancer and Other Human Health Issues:
i.
Hazardous
Chemicals in Your Neighborhood
1.
http://www.pbs.org/newshour/extra/teachers/lessonplans/science/pollution_10-3.html
Classroom
Resources and
Supplies:
a.Environmental
Chemist:
ii.
Table
I:
1.
Large
Cardboard Box
2.
Clean
Plastic Jugs or Cartons
3.
Dozens
of Aluminum Cans
4.
Paper
and Pencils
5.
Calculator
a.
Table
II:
6.
An 8"
x 10" (205 x 255 millimeters, or mm)
piece of shoe-box cardboard or stiff paper from a file folder.
7.
Six
pieces of sticky stuff. Sticky labels or
transparent tape work fine. Each piece should be about 1-1/2" x
3-1/2" (40 mm x 90 mm).
8.
One
light string per collector, 12" (300 mm)
long.
9.
One
light string per collector, 12" (300 mm)
long.
10.
Tape
to hang the collector strings.
11.
A
magnifying glass (if you have one).
b.
Table
III:
12.
5
Vials or test tubes
13.
A
graduated cylinder
14.
A
funnel straw
15.
A
marble-size piece of modeling clay
16.
4
different colored balloons
17.
4
twist ties
18.
A
narrow-necked bottle (the neck should be narrow
enough for a balloon to fit over it)
19.
A
dropping bottle of bromthymol blue indicator
solution
20.
A
dropping bottle of dilute household ammonia (1 part
ammonia to 50 parts distilled water)
21.
100 mL
vinegar
22.
5 mL
baking soda
23.
Safety
goggles for wear at all times
iii.
Table
IV:
1.
Article
to read about evaluating science
2.
Pro/Con
Handout
iv.
Table
V:
1.
Article
to read about evaluating science
2.
Pro/Con
Handout
v.
Table
VI:
1.
Article
to read about evaluating science
2.
Pro/Con
Handout
b.
Chemistry
of Cancer and Other Health Issues
vi.
Internet
Access
vii.
Chart
Paper and Colored Pencils
viii.
Appendix
A (link on
website)
Determining Solution Concentration Using
the
Spectrophotometer and Water Quality
The
spectrophotometer can be used for colorimetric determination of
concentration. The process is based
on the fact that colored ions absorb (and transmit) light from the
visible
spectrum. The greater the
concentration of ions (so the darker the color) the greater the amount
of
absorbed light or absorbance subsequently the less light that is
transmitted or
allowed to pass through the sample.
To
determine the concentration of a colored ion in solution, a set of
carefully
prepared solutions of known concentrations must first be measured for A
and %
T. This process is known as
standardization or calibration.
The spectrophotometer is set at a previously determined or
recommended
wavelength of maximum absorbance for the ion in question.
A graph plotting the A or %T vs
concentration of the standards gives a calibration curve.
The A or % T can then be measured for a
solution of unknown concentration and interpolated on the calibration
curve to
determine its concentration.
The
Beer-Bouger Law can be used to equate absorbance to concentration
providing
certain variables are held constant. The
law states
where A is the absorbance, e
is the extinction coefficient (often molar), l is the path length and c
is
concentration in M or the units of e.
e is a constant for a particular ion or colored substance
being
measured. For example the plant
pigment chlorophyll has an e value of 0.689 /(mg/ml) cm at 652 nm. Notice that the units of l are cm (most
spec. cuvetts have an l of 1 cm) and c in this case are mg/ml, so that
A does
not have any units. A is a
logarithmic ratio, that is, it is the power of 10 that the ratio of the
intensity of the original light shined onto the sample over the
intensity of
the light after it passes through the sample (log T).
Notice that if the path length is 1 cm then a graph of A
vs
c will yield a line whose slope is e for that substance.
One should also notice that if the same
substance is measured in the standard and unknown solutions using the
same
instrument then the concentration of the unknown can be found
mathematically,
A
unknown =
C unknown
A
standard C
standard
The
Experiment:
1.) You will be given a
water sample
collected from a fresh water source in New Orleans.
Write down the information from the sample bottle in your
notebook.
2.) Preparation of a
calibration curve. Prepare a data table
with the 5
standard solutions listed and your unknown sample.
The table should include a space for the concentration of
each tube (both PPM and M) and space to record both the Absorbance of
the
sample and % Transmittance.
You
will be assigned a substance to test for in your water sample. You must then retrieve the proper
standardization kit for that substance.
For each substance tested there is a set of vials of known
concentration. Exam the tubes and observe
that as the
concentration increases so does the color of the solution.
3.) To test your water
sample simply place
the long slender end of the test vial into your sample and press
sideways on
the end of the vial so that the slender piece of glass breaks. Notice that the sample end is protected
by a plastic cover so that broken glass isn’t everywhere.
Also notice that the vial is under
vacuum so that when the end is broken water from your sample is forced
up into
the vial to react with the calorimetric assay reagents.
Please do not break the sample tip out
in the air or the test will be ruined since air will enter the vial
instead of
your water sample. Wait 5 minutes
for the reaction to be complete and record an observation of your
sample
compared to the standards.
4.) Use the
spectrophotometer to read your
samples. Follow the instructions
for the particular instrument that you are using.
5.) Do not throw away any
sample
vials. Place the calibration vials
back into the appropriate box in order of increasing concentration.
6.)
Construct a calibration curve using your data. Place
A on the y-axis and concentration (M) on the x
axis. Do not graph the values for
your unknown water sample.
Determine the linear regression and draw the best fit line
through your
calibration data.
7.)
Use your graph to interpolate the concentration of ions in your water
sample
and record these values in your data table. Also
mark the values on your graph.
8.) Do additional
research to determine if
the levels of substances tested are above, below or acceptable levels
for fresh
bodies of water. You might try
finding an EPA source. Obtain data
for the same water sample from two other groups testing for other ions
and
report if these other substances are within acceptable ranges.
9.)
How would you be able to determine the precise concentration of a very
concentrated solution (> 2 M)?
Concentrated solutions are beyond the reading limits of
the
spectrophotometer.
10.) From the calibration curve and Linear
regression data determine the e for the substance that you tested. Find the literature value for e and
calculate your % error.
Statistics
Web
Resources:
http://walmartfacts.com