Sunday, February 19, 2012

Crime Busters

Crime Busters is a skills-oriented chemistry event in Science Olympiad.  Students are given a scenario and evidence collected at the scene of the (non-violent) crime.  They analyze the clues in order to solve the crime.  You can see a good description of the event at  Crime Busters on SciOly, a student wiki for Science Olympiad for exchanging tips and resources.  Note that gypsum is plaster of Paris and calcium carbonate is chalk.

Half the points are earned in the analysis portion in which students need to identify an unknown powdered solid, a liquid, and a metal.

These are pictures from the powdered solid analysis.  What you see are 11 of the 13 possibilities that I actually had around my house, even acetic acid (being a bread baker.)  Sand (go figure) and sodium acetate were the only two I did not have.

Other things you need are Lugol's iodine (not alcohol-based like the stuff at the pharmacy) hydrochloric acid (HCl), and pH paper, all available along with acetic acid from Home Training Tools.  They include instructions to make a 3M HCl solution.  You may want to get a brown glass bottle to store it in as well, and a 10 ml graduated cylinder to measure it out (though not necessary.)

The coolest reaction: vitamin C (acetic acid) turns iodine from brown to completely clear.

Saturday, February 4, 2012

Science Olympiad Practice Run

We went to a Science Olympiad practice meet to get an idea of how the competition goes.  This middle school, with no special Science Olympiad budget, allowed teams to come in and run through events.  Thank you!  They did not run all the events.  Of course none of the building events would be done. We were fortunate enough that two of the three non-building events we are competing in were available.

The above picture shows what I think is the most complicated event: Science Crime Busters. You need to know solid, liquid, and metal analysis, which earns half the points.  You also need to know hair, fiber, and DNA analysis.  You also examine fingerprints, tread marks, and splatter patterns.  After examining the evidence you then need to decide who dunnit.

The next picture is the other chemistry event, Food Science.  To prepare for it you need to do a lot of really bad baking to see how altering muffin recipes alters outcomes.  You also need a good knowledge of nutrition, which we found out we have not spent enough time on yet.  We have 5 more weeks to be ready...