mostly pesticides, in particular the smoke cones spring to mind (for greenhouse fumigation).

Want a really simple, cool experiment? Take a beaker with some table sugar in it, and pour sulfuric acid on top. First it'll just bubble a little, and then a giant black foam will form, which looks pretty cool. It does get extremely hot though and smells like sulfur though. Extremely simple and fun to watch.

ive done that

[going through history of this thread]

 

Someone asked for a source for H202; I found %27 at pool supply as a oxidizing agent. Was sure easier then trying to use fractional freezing on 3%. :-\ 27% works great for the most part, I haven't needed stronger.

 

Going to try making Sulphuric acid using H202, I never heard of that one. Thanks.

Lol sulphuric acid dehydrating sugar. That was one of the funniest moments when I first saw that giant stick of black foam. Yes that is a really good experiment. Nice and simple.

Oh, here is another even simpler experiment, but really funny too. Take equal volumes of potassium iodide and lead(II) nitrate, (both colourless), and pour the KI into the Pb(NO3)2. Yellow precipitate will immediately form.

how about making your own photograph?

 

use some of that nitric acid your wanting to make and dissolve some scrap silver into it (ask family/friends for old broken necklaces etc).

do it in a such a way that you still have a little peice of silver left over that wont dissolve, thus making sure there`s no Nitric acid traces.

 

make a 50/50 soln with it and water then soak filter paper in it and allow it to dry in a dark place (airing cuboard is ideal), make up a spray bottle of salt water (house hold salt) and spray your papers with it, and dry them again.

 

they are now VERY light sensitive!

 

put a key or something with an interesting shape on the filter paper and leave it in the sun for a few mins, the exposed areas will go Grey/Black, leaving your image as White

Hmmm... that sounds reasonable!

 

I do rem Ammonium Persulphate (the hair bleach activator contains the K and NH persulphates) being part of it, the reaction that gave the NO2 was upon the addition of Copper metal. I just don`t rem the "in Between" bits LOL

I know a pretty cool experiment. I haven't done it yet myself, but I know the procedures and I will do it soon. It is very simple. You need some flour, a vessel with a top and having holes in it, a candle and something to puff the flour up. Basically, sprinkle some flour in the vessel. Wait for it to settle down, then you put a lit candle in the vessel and close the lid. The holes are to allow oxygen in and make the candle burn. WARNING : WAIT BEFORE ALL THE FLOUR HAS SETTLED OR ELSE IT COULD MESS UP THE EXPERIMENTER AND THE THE EXPERIMENT ITSELF !!! Then make a hole or otherwise insert the puffing instrument into the vessel. When you are ready puff it. There should be a pretty strong explosion, SO BE CAREFUL ! I hope to do it soon. Please give me feedback on this. Does it work ?

Ok this is different from the post that got deleted earlier, but there is a lot of relevent information through the following link

 

http://www.scienceforums.net/forums/showthread.php?t=6641&highlight=fun+experiments

Hello I've been reading part of this topic and some of you have been talking about HCl and H2O2, and I've got a question about them:

During these days I'm going through some experiments of oxidations of sulfides in different solutions composed by a strong acid and H2O2. Preparing some samples I realized that when I mix HCl at high concentrations (from 1Molar to 12Molar) with H2O2 also at high concentrations (from 0.5Molar to 9Molar) in destilated H2O, after few seconds it start appearing bubbles in the solutions.

 

Do someone know why is this due to? if yes, could you post the reason.

 

At HCl contations about 6 and above, I thought it colud be due to the heat generated by the mixture with H2O, that made the H2O2 begin to decompose and then the liberation of oxygen was observed by bubbling. But at low concentrations this doesn't make sense.

 

I really wait for your answers. Thanks a lot!.

possibly a contaminant of some sort, as H2O2 is often acidulated to prevent such breakdown in storage (usualy by a small amount of Phosphoric acid).

Mmmm. Interesting, if these was the reason, when changing the strong acid HCl by H2SO4 or HNO3 the bubbles should also appear on not?.

 

In my experiments there are no bubbles when these other acids are used, is this compatible with your answer?.

 

Thank you so very much.

Thinking about your answer, when doing my experiments, HCl with H2O2, both at high concentrations, in dest. water, by diluting the concentration of the H2O2 the bubbles still appeared and it was till I'd diluted the HCl below 1Molar that the bubbles stopped appearing.

I can tell you for certain that H2SO4 and H2O2 will not form bubbles, as for nitric acid, I see no reason why that should either.

 

if your HCl was contaminated (maybe during manufacture or use, depending on it`s Grade) that could cause the H2O2 to breakdown, but something in the vessel if not properly cleaned could do the same.

Thanks again!.

 

So, the reason you think is the most provable is due to a contamination of the sample during the experiments. The thing is that I've repeat the experiments so many times with HCl at high concentrations, always generating bubbles, to be sure that is not due to contamination. And as I'm concerned that is not due to the H2O2 concentration I thought it had to be due to some reaction between the acid and the peroxide in water which should involve the breakdown of H2O2 maybe by an increment in Temperature or something similar.

 

I will appreciate any other suggestion or explanation.

test the gas to see what it is

It's O2.

Lol sulphuric acid dehydrating sugar. That was one of the funniest moments when I first saw that giant stick of black foam. Yes that is a really good experiment. Nice and simple.

Oh' date=' here is another even simpler experiment, but really funny too. Take equal volumes of potassium iodide and lead(II) nitrate, (both colourless), and pour the KI into the Pb(NO3)2. Yellow precipitate will immediately form.[/quote']

and you get left with a solution of KNO3 i think.

seen it, it's quite good.

Yup. That's another method of making KNO3. Lab demos are always great. That's why I always make sure I go down to the local University when they do their chemistry demonstrations. No matter how many times I've seen it, a thermite reaction and anything involving liquid nitrogen is too much fun to miss.

kind of off topic, but i just happened to hav went to a college chemistry show a few days ago.

your point is???

 

perhaps a College English demo would have been more appropriate