[mike]

My favourite chemistry experiment from high school/first year university level chemistry was probably extracting the coloured components from spinach and running a thin layer chromatogram of them. I think because it was colourful and relatively "consumer based" chemistry I found it interesting.

I now have a job introducing new experiments into a first year general chemistry program and it is quite fun. I have found literally thousands of experiments uploaded on the web and in educational journals covering every topic imagineable.

I would love to know what kind of experiments people on this forum remember/enjoyed and why. Do you think there are certain types of experiments that excite students about science more than others?

Cheers, Mike

[billnotgatez]

You might find this site interesting especially the lectures.

http://cavemanchemistry.com/
http://cavemanchemistry.com/ch104.html
http://cavemanchemistry.com/lectures.html

[mike]

Cool, yes these are the types of things I think make chemistry/science interesting. Looks like a great site I will have to sit down and have a decent look at it in a bit, from the quick look I have had seems very interesting.

Thanks

[ATMyller]

We didn't do much experiments in high school, but one I remeber being interesting was Aspirin synthesis. Quite simple reaction creating a pure drug component, showed how simple chemistry is in theory, but not quite so easy in practise.

[lemonoman]

The presentation that I remember most were demonstrating the effect of surface area on reaction rate (a lesson I haven't forgotton!)

Cheesy and insignificant as it sounds, the teacher took some lycopodium powder..put it in a pile, and lit a match and put it on top.  The powder kinda fizzled a tiny pit...but the flame got extinguished.  Then he took some lycopodium powder in his hand, and held a lit match between his fingers.  He jerked his hand upward so the powder would spread up and outwards, passing the match in transit (obviously with a greater surface area).  The powder combusted into a short-lived ball of fire...like 2 feet tall and one foot wide.  It was AMAZING!

I also remember when he took a particular crystal that could exist with or without a water of crystallization...He heated the hydrated one to dispell the water and it actually changed colour (neat eh?  I know now that that's ligand chemistry )...

Anyways he had one guy put it in his hand, and then he put a tiny drop of water on it.  The crystal readily recrystallized, and of course gave off some heat in the process...I remember the guy holding the reaction in his hand uttering an expletive lol...Heat of hydration is AWESOME (is that what its called)?

[jdurg]

I always got a big kick out of the alkali metal and/or halogen reactions.  There's just something about them that is always fun to watch.  Whether it's an alkali metal in water, or a metal burning in a pure halogen atmosphere.  (I really enjoyed aluminum and iodine and aluminum and bromine).  I guess the real kick out of those experiments was the fact that they weren't done all that often as the halogens and alkalis are incredibly reactive.

Another neat experiment was done in college where we synthesized nitrocellulose and nitroglycerine.  Now this was done on a microscale where one cotton ball was nitrated and one mL of glycerine was nitrated, but it was still neat to see the stuff beforehand where it would barely ignite (cotton), or do nothing at all (glycerine).  Then it was nitrated and suddenly the cotton immediately flared up and dissapeared in a ball of fire, and the glycerine just went 'POW' and it was all gone.

[Blueshawk]

My favorite experiment was done in my garage with a microwave.

I took a piece of cork and stuck a toothpick in the top of it.  I then place that in the middle of the microwave.

Then I took a large Pyrex beaker, i think it was 2 liter, and coated the inside with honey and salt.

I then light the toothpick on fire, placed the pyrex beaker over the top of it and set the timer to 30 seconds.

After a few seconds, a glowing orange and red "plasma" ball was floating or clinging to the top of the inside of the beaker and swirling around.

Very cool, but dont expect the microwave to last for too long:)

[mike]

If only there weren't so many occupational health and safety issues with so many of the "fun" experiments, we could really spark students interest in chemistry. My father always says that experiments that go boom give students the wrong idea about chemistry. I think we need a balance of both types of experiments, visually spectacular as well as those that inspire thoughts of chemistry on other levels.

I think demonstrations like making nylon, lighting light bulbs from chemical cell, and the luminol reactions are all quite good in this respect. Liquid nitrogen demos are spectacular too, and I always loved dry ice when I was younger.

[constant thinker]

My physical science teacher (Freshman year)took a mixture of soap and water and hooked it up to the gas jets. He then proceded to take 2 yard sticks; 1 with a flaming ball of alcohol/water mix in a napkin and the other yardstick he took the bubbles and proceded to light them on fire. All of this was to show us the consvation of energy and reactions. Sure this wasn't the safest thing but they hadn't installed the sprinkler system yet   .

Another cool thing he did that wasn't so dangerous was took he took a drained out egg and put 2 chemicals in it. He didn't tell us what he put in it for "safety" reasons but the reaction gave off hydrogen gas and the egg exploded under pressure. This demonstrated pressure.

[mike]

Ok so now I have tried dehydration of sugar with sulfuric acid and the thermite reaction for myself, and they are pretty cool. We are going to introduce these into the undergraduate labs, hopefully the students will be suitably impressed.

[Alberto_Kravina]

My favourite experiment is the Marsh test (detection reaction for Arsenic)

[Mitch]

Ok so now I have tried dehydration of sugar with sulfuric acid and the thermite reaction for myself, and they are pretty cool. We are going to introduce these into the undergraduate labs, hopefully the students will be suitably impressed.

I did the sugar and sulphuric acid reaction too several weeks ago!  I tried several different artifical sweetners and the same fianl product was seen with all of them.

[mike]

I tried several different artifical sweetners and the same fianl product was seen with all of them

What a great idea, I never even thought of trying artificial sweeteners, I will give it a go.

Do you think that syrup would work? Maple syrup or golden syrup, molasis? interesting!

[Mitch]

Since sulphuric acid is acting as a strong oxidizer. One would expect it to oxidize any hydrocarbon species to natural carbon.

[jdurg]

My favourite experiment is the Marsh test (detection reaction for Arsenic)

Ahhhh yes.  The good 'ole Marsh test.  We did that experiment in our toxicology lab.  If I remember correctly, the presence of arsenic shows up as little dark spots in the solution, correct?  I think one of the intermediates is the production of arsine gas which led to a bit of a scare in our lab.  (One of the reaction vessels was erroneously taken out of the fume hood, and my nose was able to pick up on the rotted garlic odor.  Oddly enough, nobody else noticed the arsine smell but me.  Go figure).