" I use gummy worms rather than bear because they fit better in the test tube. I do the demo when we study the relative reactivity within a family, and I compare the color of the flames and the reactivity of NaClO3 and KClO3. At the end the students can smell the burnt sugar, and relate it to marshmallows. I show also video clips to make the same point but this is a demo they and I like. And I never had a problem with it. In my opinion it is ok to do this type of demos as long as you know the danger involved. But I like the idea of burning of paper in the presence/absence of NaClO3. Thanks. M. Zamora ----- Original Message ----- From:<neact@xxxxxxxxxxxxx> To: neact digest users <ecartis@xxxxxxxxxxxxx> Cc: Date: Tuesday, January 6 2009 2:01 AM Subject: neact Digest V5 #3 neact Digest Mon, 05 Jan 2009 Volume: 05 Issue: 003 In This Issue: [neact] Re: potassium chlorate and gummi bear [neact] Re: potassium chlorate and gummi bear ---------------------------------------------------------------------- Date: Mon, 05 Jan 2009 11:46:52 -0500 Subject: [neact] Re: potassium chlorate and gummi bear From: "Sue Klemmer" <Sue_Klemmer@xxxxxxxxxxxxx> Here's a live demo that's a bit less hazardous. I do this with plain paper and sodium chlorate. I put the NaClO3 in a small evaporating dish on a hotplate in the hood. I have several half-sheets of paper handy. First, outside the hood and over a sink I light one piece of paper on fire with a match, and while they watch it burn we review ideas about combustion: esp. the idea that oxygen is usually the limiting reagent when burning paper, hence the ash residue. Then I take another piece of paper, crumple it into a ball, and drop it in the dish of melted (and decomposing) sodium chlorate. The paper ignites rapidly (hold it down with tongs or a glass stirring rod) and burns brightly and completely to carbon dioxide and water vapor. A hefty tablespoon of NaClO3 will let you burn one piece of paper - I usually put in enough to get 2-3 pieces burned. When the sodium chlorate has fully decomposed, the next piece of paper you put in the evaporating dish burns "normally" to ash. (That way you know all the chlorate has decomposed.) While the gummi bears are a more spectacular event , I like the paper because of its familiarity to students (and easy cleanup). They are less likely to think there's something "magical" sheets of paper than in gummi bears. You can then connect this to other oxygen-enriched or environments (why do you blow on a fire? why do oxyacetylene torches have an oxygen supply? why is it so often a fatal fire when people smoke around an oxygen tank? why do athletes do blood-doping?) In addition to the videos mentioned before, you can follow up with the 1 minute clip from October Sky (where they dump KClO3 down the sink in the lab and someone else ads a spent match) or the old 25 minute Film for The Humanities "Explosion on the Lady Delia". Susan A. Klemmer Chair, Science Department Camden Hills Regional High School 25 Keelson Drive, Rockport, ME 04856 PS It wasn't clear whether this demo was about combustion or energy. If you're into the energy concept, here's another favorite demo that's not very hazardous to do but memorable to students and takes under 5 minutes. Get a small bag of baked potato chips and a bag of cheap fried ones (cheaper the better). Hold a baked chip in a bunsen burner flame with tongs and note how it burns. Then burn a fried chip: it burns brighter and faster, and will often drip burning fat. Ask the class to tell you why they burn differently - and have them check the caloric contents on the bag. ------------------------------ Date: Mon, 05 Jan 2009 15:22:09 -0500 Subject: [neact] Re: potassium chlorate and gummi bear From: Dave Crockett <dcrockett@xxxxxxxxxxxxxxxxxxxxxxx> Hi! I did this demonstration and burned my hand because the gummi bear wouldn¹t slide down the tube and I foolishly ramroded it in using a combustion spoon which I should have bent back on itself to be safe but didn¹t... A much safer demo that unfortunately doesn¹t involve a sacrifice is called the M&M massacre. I use 2 M&Ms- they slide down the tube easily and don¹t stick...avoid the temptation to keep putting in more M&M¹s even though there may be a lot of leftover molten potassium perchlorate. The kids loved it....I am a teacher who likes to ³fire² students up once in a while with this sort of thing... I save the videos for things I really can¹t do myself like thermonuclear explosions.... Dave Crockett On 1/2/09 10:54 PM, "nancyjeanward@xxxxxxx" <nancyjeanward@xxxxxxx> wrote: > > Hello. I am contemplating doing a demo with gummi bear and potassium > chlorate; however, I am a bit chicken. Could you give me any info on this? > Has any one done this? > Thanks, > Nancy Ward > > -----Original Message----- > From: Kenneth W. Brody <kwbrody@xxxxxxx> > To: neact@xxxxxxxxxxxxx > Sent: Fri, 26 Dec 2008 12:43 pm > Subject: [neact] hope to see you > > I apologize for this listing: I usually read the notices I read with a more > critical eye before sending them to the list-serve. I guess the holiday > season highs made me miss this. The response I got indicates how shop you > guys are. > > Sorry, and Happy New Year. > > Ken > * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * > * * * * * * * * * * * * * To post a message to the NEACT list, send an > email to neact@xxxxxxxxxxxxx To unsubscribe, send an email message to > neact-request@xxxxxxxxxxxxx with ?unsubscribe¹ [without the quotes] in the > subject field. You may also unsubscribe via the web interface at > //www.freelists.org/list/neact . Help with the system may be obtained > at //www.freelists.org/help Archived messages may be accessed at > //www.freelists.org/archives/neact ³Digest² mode: Subscribers may set > a flag to this effect, whereby all messages during a given day will arrive at > the end of the day as one email message. Please see the Freelists.org help > files, or log on to the web portal for instructions. > ³Vacation² flag: It is also possible to set this option, which will cause > messages to not be delivered for the length of time that you specify. Here > too, please see the Freelists.org help files, or log on to the web portal for > instructions. > Moderator: The moderator of this list is Steve Stepenuck, whose contact > information is on the NEACT website at http://www.neact.org/list_service. > Please contact him if you encounter any problems subscribing to or using this > list. Thank you. > > > Get a free MP3 every day with the Spinner.com Toolbar. Get it Now > <http://toolbar.aol.com/spinner/download.html?ncid=emlweusdown00000020> . > ------------------------------ End of neact Digest V5 #3 *************************