[jdog3131]

Alright so I'm an 8th boy in school and we do a turn about day where we are the teachers and we have 45ish minutes to teach to th kids and do something fun. And being the chemist I wanted to do someth chemistry related. But I can't think of anything but experiments involing fire or fumes or something really dangerous. Now don't get me weong I'm not opposed to dangerous but I want it be ok for 5th graders. So anyone have any ideas?

[Borek]

So basically you are asking for an interesting, easy and safe experiment?

A lot depends on what kind of reagents and in what amounts you can use. Plus kinds of glass that you can use.

Simple and interesting experiment is this one:

http://www.youtube.com/watch?v=ZlCcn5aoa-U

You don't have to start with the dry ice, you can produce CO₂ from carbonate using a gas, to add initial sizzling and bubbling to the experiment.

[curiouscat]

Try the Chemical Oscillator? Looks cool. They've no chance understanding it though. 

A simple titration might look cool too with colorful changes. You don't even have to bother with burettes etc. just add things till colors change.

A Silicate garden?

[billnotgatez]

you might look at this sticky on this forum

http://www.chemicalforums.com/index.php?topic=8986.0

Not all the links inside the thread are good but some still are OK

One suggestion -- practice several times to make sure you got the hang of it and keep the results so if you demo fails you can show the results anyway

[jdog3131]

Thank you guys for your reply's. I enjoyed looking at the links and the ideas and I have an idea forming. I think that I might do something with the 5th graders trying to figure out which substance is a acid (via  titration) out of some (maybe vinegar,water,oil and maybe some other liquid). Then after they try get the vinegar as their acid, we'll try out the bubbles an CO2. To bad I couldn't find any age appropriate link I liked for the last link, though those could come in handy for my self one day. Thanks:)

[billnotgatez]

Could you post the link you like

[jdog3131]

Yeah sure. Also sorry about posting the wrong forums. So i will give the kids water, milk and white vinegar. They will then be given red cabbage extract type stuff. After this I will tell them what to look for when they add the liquids. When they find that the vinegar is the acid we will set up this http://www.youtube.com/watch?v=ZlCcn5aoa-U but instead of dry ice use baking soda and vinegar. Sound good?

[Arkcon]

There are other gasses that are easy to generate:  you could also inflate balloons with carbon dioxide, air (from an air pump) or hydrogen from the reaction of weak acid (vinegar is fine) on an active metals (the zinc plated onto roofing nails is fine.)  The balloons will inflate with the colorless gasses all the same, but the hydrogen balloon should float (if you fill it enough) and the carbon dioxide balloon should drop.  If you really like the soap bubble experiment, the bubbles will likewise sink or float, for carbon dioxide or hydrogen.  There shouldn't be ignition sources in the classroom, so soap bubbles of hydrogen shouldn't be a hazard.

[curiouscat]

Knowing these are 5th / 8th graders hydrogen might be a bit iffy? Especially with a balloon floating around?

There shouldn't be ignition sources in the classroom, so soap bubbles of hydrogen shouldn't be a hazard.

With H2 isn't everything an ignition source? Even a switch or a fan? OTOH, maybe they'll only be tiny pops.

[Arkcon]

From a soap bubble a pop would be heard.  From a large rubber balloon, that would be dangerous if ignited with an open flame that melts the rubber.  But there shouldn't be open flame in a grammar school science lab, I doubt there are many children with a smoking habit, and its not a concert either.

[billnotgatez]

@jdog3131
you might want to consult with the teacher to let them know what you are going to do