Chemistry help

[junior elf]

Ok, I\'m just making a mini balloon and I need a chemical reaction to make it fly. So here are what I need: substances that will react slowly and that are exothermic as well. So far all I\'ve found are stuff that have super fast reaction and that are so exothermic that they are likely to burn the balloon.

Thanks in advance,
JE

 

[Shadzar]

Well that removes thermite from the list.

I know there is some kind of two part insulation foam than gets hotter as it expands.

Not sure how slow the reaction is.

 

[Amazon warrior]

What\'s the balloon made of? How\'s it set up?

 

[Farin]

k, I\'m just making a mini balloon and I need a chemical reaction to make it fly.

I think the better way is to use a reaction that produces enough hydrogen gas to lift your balloon - hydrogen has a fairly big buoyancy force so you won´t need much. Try to find a base metal ( don´t take alkali metalls since the reaction is to severe, magnesium should be fine and easy to find ) and something that contains a fairly strong acid - maybe there´s some brand of household cleaning agent in your area that contains acid. The reaction will still be exothermic , but the heat should be manageable if you dont use giant amounts ( NEVERTHELESS, BE CAREFUL , remember to wear goggles ), also it won´t be as superfast , since the metall needs some time to dissolve.

Oh and just as a reminder: 1 mol of a gas has a volume of 24 litres at twenty degrees celsius. Hydrogen has a molecular weight of 1, so with n=m/M, you only need 1 gramm of Hydrogen to fill a ballon of that volume. ( for more information check your chemistry textbook or wikipedia )

Hope that´s helpfull

Farin

 

[wiccanpony]

if you blow up the world, we\'re coming to get you:cussing:

 

[Farin]

if you blow up the world, we\'re coming to get you:cussing:

lol

Don´t worry a little hydrogen should be no biggy - unless he want´s to reinact the Hindenburg catastrophe

 

[nels0nmac]

For a basic way of making it work how about a nearly finished tea light, or a small piece of candle
. I tried a mini balloon as a project when I was in cadets. It was made out of thin strips of card and tissue paper. Unfortunatly we weren\'t allowed to use bits of candles to launch inside... some health and safety nonsense about burning balls of flying tissue setting off fire alarmslol. Anyway we tried a hairdryer but that did not create enough lift to make our balloons work. We were assured that if we had been allowed to use bits of candles they would have stayed aloft for quite some time.

 

[junior elf]

Thanks Farin. I think your right, magnesium seems to have the correct properties. The only acid I can find that seems to work well is hydrochloric acid. The only thing left now is to get my hand on these. Does anyone know where I can buy them in London?

Thanks to everyone else who replied too.
JE

 

[TAB Studio]

I find hydrochloric acid in rust remover called Iron out here in the states. I also find gallon amounts at Home depot or the hardware store for the same purpose. Gloves required or it gets under your fingernails and is quite painful.

 

[RuneBrush]

Try going into a chemist\'s and asking if they stock it or are able to point you in the right direction. I\'d guess that it\'d be obtainable, but not that easily.

 

[Farin]

I find hydrochloric acid in rust remover called Iron out here in the states. I also find gallon amounts at Home depot or the hardware store for the same purpose. Gloves required or it gets under your fingernails and is quite painful.

well, one should ALWAYS wear gloves when working with strong chemicals ( even acetone for stripping miniatures dries out your skin , so at least one should use some creme afterwards - Nivea or whatever is handy ) - especially acids and lyes.

acid burns are nasty , but lyes are actually worse since lye disolves fat . And our skin is basically fat, since every cell is a system of membranes made of phospholipids ( fancy science talk for fats combined with phopsphor ). If you can´t imagine what happens , watch fight club.

Okay back to topic

yep that rust remover sounds perfect.

If you haven´t done this before i strongly recommend that you read a good chemstry textbook: Constable and Housecraft: Chemistry is a great book . I own the international edition and it´s one of the best textbook for chemistry i know. Plus it starts with the absoulute basics. Even more important try and find someone who is willing to do this with you and who has maybe even have some experience.

Oh and of cause no open flames or sparks when working with hydrogen, i guess you already know that, but i wanna be sure .

 

[Shawn R. L.]

Did some \'junior experimenting/inventing\' as a lad with hot air balloons and had phenomenal success......flames were carried aloft along with a firecracker one time. Won\'t go into any detail as I want no responsibility to any ensuing disaster.

 

[Einion]

Originally posted by junior elf
Does anyone know where I can buy them in London?

If you\'re in the UK you\'re very unlikely to be able to find either for sale to the public.

In the US on the other hand you can buy muriatic acid (hydrochloric) in most hardware stores! It\'s for cleaning grout and concrete among other things.

Magnesium is still something I think you\'d have to order from a metals or chemical supplier; it\'s dodgy stuff in quantity, since if it ignites it can\'t be doused using water. You could be able to get it from wrecked cycle frames (probably alloyed though) but without the HCl there\'s no point.

Einion

 

[green stuff]

Not to burst everyone\'s bubble, but wouldn\'t helium be safer?!?

I\'m sur you can find small canisters that\'ll do the job.

 

[BPI]

If you just mean a PVAed tissue-paper balloon then the way I did it as a teenager was to string a square of ? (square of metal mesh with white stuff in a circle in the middle, put over tripod with bunsen burner beneath & pyrex on top in chemistry class, heat mat?). Bung a parrafin fire-lighter on top, light. Balloon fills with hot air & quickly lifts off. If the wind is calm it drifts off over the countryside (looks nice at night) & if it\'s too windy it cartwheels away in a flaming ball of paper & parrafin & you get to start again lol Don\'t set it off where it\'ll carry over housing, etc.

B.