SPP SciO wrote:
dholdgreve wrote:I ran this event recently. Regarding the Calorimeter, I felt that it was unrealistic to expect these middle school age kids or younger to build a device such as this, then compare their data to the stated caloric values from the manufacturer who used equipment in the thousands of dollars. Yes, we still did the lab, but rather than look for the correct answer, we reviewed the work based on organization, data collected (did they collect all the info that was needed to perform the calculations, and was it properly labeled), the basic calculations of reducing the heat gain / total amount of water to heat gain / ml, the equating of this to calories, the conversion of the calories to joules using the correct constant, and ultimately the comparison of their results to the stated caloric values (% efficiency) of their unit... Ya... nobody got that far... but if they did, we would have been ready!
My suggestion to those doing and running this event is "Make the Best of it." Instead of focusing on building the best possible calorimeter out there, focus on an very organized report format that clearly documents the entire procedure... Don't worry that your 2 soda cans only had a 28% efficiency... it doesn't matter... What matters is can the event proctor clearly follow your logic path, and have you conveyed through your records that you totally got this, and understand every single thing about the calculations. And to those running the event, I respectfully suggest that you focus on the process as opposed to the results. It will make grading a whole lot easier and less subjective.
When you ran this event, how much time were the students given for the calorimeter portion? I'm thinking that the scales required must be a limiting factor - it would seem unreasonable to run this event without a scale capable of measuring to the 0.01g, and it's unlikely that most competition sites would have more than a couple of them available ... Will the teams be called individually to the calorimeter station at some random point during the 50 minutes? Is it a wise idea to have one partner be the calorimeter specialist, so the other partner can continue working on the test - similar to Optics?
We set the Event up in 2 Parts... Part 1 was set up in (7) 5-minute Stations. Each station had several questions, and most had a small lab at the end. As you can imagine, trying to come up with that many mini labs on grain is next to impossible. While we really tried to focus on grains (Having 2 stations totally dedicated), we also did a "Salt concentration of various noodle soups" lab where the kids were able to use their conductivity testers to put 4 samples in the correct order of salinity. We also did a Vitamin C / Lugols titration of 4 samples. Anyhow... The Stations took 35 minutes. This left about 20 minutes for the kids to do their Calorimetry. We set of the Part one stations at opposite ends of the room, and had a couple of Volunteers "ride herd" to make sure everyone progressed in the correct direction. At the end of Part one, Each of the 13 teams came to a central table in the room. This table contained a bowl of Fritos, a bucket of water (with thermometer, if they wanted to use it, and (5) scales that measured to .01 grams (These are not as expensive as you might think. We bought all 5 for less than $70.00). As part of the kids instructions, I suggested that they make sure they use the same scale to weigh their ash as they did to weigh their sample, as their could potentially be slight differences in the way the scales are calibrated... (there was a difference of .04 grams from high scale to low scale)... This tournament was set up for only 26 teams. We had 2 sessions of 13 teams each, and sharing digital scales did not seem to bottleneck anything the way triple beam balances would have.
For those of you scheduled to run this event, and like the way we set it up, one word of caution... TAPE THE STATION TESTS DOWN to the station table... We had one group walk off with one of our laminated station cards with all the questions on it! We looked, asked, investigated, and never did find it... I had no back ups of the cards, never in my wildest nightmare imagining this would happen... So I told one of our teams to start their calorimeter test 5 minutes early, Ran to the computer lab, downloaded another copy from dropbox, printed, and returned within 5 minutes... When all the other teams were starting their calorimeter testing, I had our team run their last station for 5 minutes, then go back to the calorimeter thing... Ya... not a good situation, but as close as we could get to being fair.