♪[theme music]
>>teacher: Today what we're going to do is, we're going to start our project on
uh forensics. So a lot of you guys have watched CSI maybe. Right? And you know you can
see that they solve the crime in an hour. Right? And then
not only do they solve the crime, they can tell you
backstory of everything that happened. Ok? And that's going to be essentially your job.
What you're gonna do is, you're going to utilize
all of the labs that we've done recently in
order for you to analyze evidence and data to put the picture together as to
what happened in the crime. Ok? So this project is essentially kind of like a
capstone. A capstone project is essentially a culminating project um that
it asks the students to use the skills they've learned in the class and kind of put
it together and complete an investigative project. It's a capstone project because
it basically is the culmination of everything that you've done in class so far. You've
learned how to do titrations. You've learned how to do
um analysis of solutions using a using a
spectrophotometer. You've learned how to do
calorimetry and density, and way back in the
beginning you also learned how to do chromatography.
Do you guys remember all that? Now you should have all of these labs already
in your notebook, and so when I allow you to do the experiments, I'm not giving you
you directions on how to do it because - it's all - in your notebook.
On the first day of the project essentially what I did
was I introduced the crime to the students.
On the night of April 15, 2015 there was an industrial fire at Allied Union. Allied
Union is the name of the company. Now Allied Union is an explosive manufacturing
company, so they make explosives. Now due to the explosives and the chemicals
that were present at the site, it took firefighters
two days to put out the fire. So there
was extensive damage done to the structures.
Ok, your job is this: You're gonna work in groups of four,
and no more than four. And you're gonna
analyze the evidence and you're gonna piece
together what you believe happened. You're going to
produce a poster that summarizes your results, identifies who the suspect is,
and gives a reasonable explanation for the crime. You have to discuss the motive and
you have to support all of your claims with evidence from the experiments.
On the first day each group performed a particular experiment. So what I did was
I numbered of the groups. Um, groups
1 - 8. And on the first day groups 1 and 2 would be investigating
the chromatography experiment. >>student 1: Ok, we're testing the chromatography of
and like-we have like different pens from each like person. And then we have to
test each pen and see which one matches the note. That way we can decide who did it.
>>student 2: So like this is kinda like a big old pot of past labs.
So we're just looking at our past labs that we've written and
we're following the same directions and applying it to this one.
>>student 3: It starts out dark right here, right? I don't know if you see it but
it, but there is a little bit of red right there. Right where it says...
>>student 4: Yeah. >>student 3: You see it? >>student 4: Yeah, I see.
>>student 3: Then it gradually... >>student 4: I see-I see a little bit of red on that one too.
>>student 3: As it gradually gets-goes up, the colors start to identify:
yellow, yellow, blue, blue, on top, purple. Robert.
>>teacher: Groups 3 and 4, they perform the water sample analysis. So
samples of river water taken from around the area where Allied Union, the made up
company, was located.
>>student 5: Uh we're testing the acidity of the water found at the crime scene.
So we're adding base and we're calculating how much
base we add to the water. And depending on how
much base that we add into to the water, then we can determine how much acidity
the water has.
>>student 6: I think that the contamination started upstream because it...uh...wait
>>student 7: It was darker when you added more base.
>>student 8: Just because it's darker doesn't mean that it's contaminated because
the base cancels out the acid, so if there's less base needed to you
know turn it pink and then that means there's less acid in the water..so
if there's less acid that means there's less toxic waste. So
I mean which one took the most base to...you know like turn pink?
>>student 6: So they're contaminated. >>student 7: So they are contaminated. >>student 8: Right.
>>teacher: My role during the investigation was to act as the facilitator. The students
themselves-they should already have the skills needed in order to do the lab. But if
I notice that a group was struggling, I would walk over and kind of give them
some guiding questions to put them on the right path.
Steve Profit could be the-the culprit? Why? >>student 7: He was trying his best to
minimize costs and to maximize profit. >>teacher: Ok. >>student 7: Therefore by dumping the
toxic waste in the river he wouldn't have to pay for disposal service.
>>teacher: Oh, okay. Aright, so he has a motive. Does anyone else have a motive? >>student 7: Cici Arbold...
>>teacher: Groups 5 and 6 - they were responsible
for analyzing a sample of a fluid that was found at the scene.
>>student 8: We're gonna pour the solution.
into a test tube and we're going to dilute it with water to um...
>>student [unseen]: Get the concentration. >>student 8: Get the concentration.
We're going to get a cubette and put it into this, which is already calibrated and
and everything and it's gonna tell us the-the... >>student [unseen]: Concentration
>>student 8: Concentration. And we're gonna record all the data down
and basically with the data we collect, we're gonna make
our self a graph with um- best fit line so we can find the
concentration of this unknown fluid found at the crime scene.
>>student 9: We did a serial dilution. We started with 9 mls
of water and 1 ml of bpb, >>teacher: Uh huh.
>>student 9: And we diluted it down by half and half and half >>teacher: Ok.
So what did you do to the concentration every time?
>>student 9: We divided by-into 2. We halved the parts per million.
>>teacher: The last two groups - groups 7 and 8, they were responsible for
analyzing some metal casings that were found near the crime scene.
>>student 10: So there was a bullet casings found at the scene.
So this lab is testing the metal that we
have. And we are trying to see if it matches with the metal-with the metal of the
bullet casing that was found at the scene and trying to figure out who-who shot
the gun ...yeah who shot the gun and what gun it came from.
>>teacher: The following days they would each then rotate to the next lab. So
after all the investigations were complete the students were given time to
put their evidence together in a poster.
>>student 11: Right at like Allied Union it was the most acidic, right?
>>student 12: Yeah. >>student 13: They weren't disposing it the way
it was supposed to be. >>student 11: Oh yeah.
>>student 13: Since we're blaming the CEO, do you want to have all the reds
pointing to him? Or should it be reds pointing to other people too?
>>student 14: Well there can be reds, um... >>student 15: different colors for
each person. >>student 14: Well, no because then...
>>teacher: The gallery walk is a teaching strategy
that allows students to be actively involved. So I wanted to make sure that
every student was involved in listening to a presentation and evaluating it.
>>student 15: Our third task was to identify a
mysterious liquid found at the site of the crime scene.
Uh, we used-we used a spectrophotometer to find the concentration of the liquid and
we found it to have a concentration of over 7.5 bpm meaning that
it was an accelerant believed to be kerosene used to start the fire. But-and then from
these pieces-from these three pieces of evidence we now know who has the will,
motive, and determination to burn down Allied Union...
>>teacher: The advantage of doing a gallery walk is that the students
are actively engaged. They're up, they're moving about, they are
involved in the whole process. And they're buying into what they are doing.
>>student 16: Upstream... the-the water was very
neutral. We had to use very little um base to make it
basic which means that it was a neutral solution upstream.
Um, at the site of the river it-um we used 9.3
mililiters which is a lot more than upstream. So and
basically that means that it's at the site; it was very acidic whereas
upstream it was not which means that Steve Profit
and his company were dumping acids in the river.
>>teacher: The one thing that I wanted all my students to
to be able to show me in this capstone project was that they had the
ability to criticallythink.
Tell me-tell me what happened upstream, tell me what
happened at Allied Union, tell me what happened downstream,
tell me what your data tells you about the toxicity
of the river throughout the whole process.
>>student 17: Okay, so upstream it's very very clean, very neutral
but as soon as you get to the site of Allied Union's use, you'll see that it's like
acidic, the water, meaning that they poluted the river. And then downstream it's
a little less acidic because like when you move downstream
it's like solution is a little less than it is at the site.
>>teacher: Okay, so most of the polution occured where? >>student 17: In Allied Union.
♪[theme music]