Plastic Soda Bottle + Alcohol = Rocket

[Mark]

If you use salt, you will make hydrogen and chlorine. The H2SO4 or NaOH should give you hydrogen and oxygen. I've used a carbon electrode, but yes platinum would be ideal.
Mark

[Mark]

An interesting thing about hydrogen and chlorine is that if you make it and keep it covered in a glass container and then uncover it out in the sunlight, it will detonate from the minute amount of energy from the ultraviolet light. Turpentine eye droppered into a flask containing chlorine gas will burst into flames.
Mark

[El-Kablooey]

If you use salt, you will make hydrogen and chlorine. The H2SO4 or NaOH should give you hydrogen and oxygen. I've used a carbon electrode, but yes platinum would be ideal.
Mark

Really? I thought the NACL was preserved, you can electrolyze salt, but I thought you had to melt it. If electrolyzing salt water releases hydrogen and chlorine, where does the sodium go?

[Mark]

NaOH
Read the last line in the Occurance topic. Chlorine is hard on your electrodes too.
http://www.absoluteastronomy.com/encycl ... lorine.htm
http://www.answers.com/topic/chloralkali-process
http://electrochem.cwru.edu/ed/encycl/art-b01-brine.htm
http://www.bellona.no/en/energy/hydroge ... 22871.html

[Dang911]

Never though of that, but looking into it, your half right. Saltwater would turn into Chlorine gas and the Sodium and water would be turned into Sodium Hydroxide (NaOH), which then would be split into Hydrogen and Oxygen though electrolysis.

So we have 4 byproducts here (balanced I think), Chlorine (Cl4 g), Hydrogen (H4 g), Oxygen (O2 g), and Sodium (2Na s). So everyone is happy here!!! We get some Hydrogen and some Oxygen, even some Chlorine gas too, watch out!!! Then if I stand correct, we should be left with solid Sodium, how exciting that stuff is to play with, well you guys saw what I do with it in the sewers on page 2!!!

So who ever told me to use NaOH in the first place, wins the prize, they were 100% right. Its probably the most efficient way to create Hydrogen and Oxygen though electrolysis. By the way to make NaOH, its really easy, I believe you can just mix lye (be careful very costic) and water....Right? Now I have to go do all of that, and I will comment later.

[pezman]

As a variation, put calcium carbide crystals in a little nylon bag in a water rocket and let the water cook up some Acetylene.

[Mark]

Sodium is just going to react with the water before you start dreaming too much.
If you just want to make hydrogen, zinc and hydrochloric acid will do fine. You can buy muriatic acid, (hydrochloric acid), at any store like Lowes or Home Depot for cleaning sidewalks or whatever. The new pennies are just jacketed in a fine layer of copper. If you nick the edge of one and put it in some HCl, it will eat up the zinc and leave a papery shell of the coin.
Don't blow yourself up of course. Explosions are kind of boring after awhile. Here's an interesting read on some of the hazards of working with things that go bang. Pierre learned the hard way. Please be careful.
Mark
http://www.chm.bris.ac.uk/motm/ni3/ni3j.htm

[El-Kablooey]

ok... I guess you will get a small amount of chlorine at first, until it is gone and you have a NAOH solution. That still beats the crap out of using H2SO4. I guess starting with NAOH would be better, except salt is in every home, and you don't get followed home from the store if you run in and buy a box of morton salt.

[Dang911]

I have done the penny shell trick many times. I have also made gold look alike pennies in my AP Chemistry class by carefully coating the outside of a penny in zinc by electro plating, then oxidizing it slightly on a hotplate. It then turns gold around a certain precise temperature from oxidation, and you can't tell the difference between it and real gold. The only difference, is in about 3 months, more oxidation will take place and the gold will turn back to brown.

As far as making hydrogen, zinc will work, but I have also used Magnesium (Mg) mixed with hydrochloric acid.

As far as the tri-iodide crystals I have made ammonium tri-iodide crystals, and they are a lot of fun. Super simple to make, you just have to be respectful, and use them right after you make them. DO NOT STORE THEM, or make batches grater than 100g..

[Mark]

When I was very young I use to make hydrogen by using NaOH and aluminum foil. It makes a lot of heat when you mix NaOH with water and the fumes can be kind of choking. NaOH disolves skin pretty good too. You can put magnesium in methanol and make hydrogen too. And of course if you had some sodium you could just put that in some water and collect it that way. I remember blasting chunks of sodium in a backwater slough off of a river in Oregon when I was high school age. I then took a glass jar with hole in the lid with some rocks and sodium and sunk it. Unfortunately, it only bubbled profusely, because the hydrogen had nothing to burn with or ignite it when it arrived at the surface. Had little pieces of sodium melted and escaped and floated to the surface, I would have been in business, but as such, it was a dud of an experiment.
What are you planning to do with your hydrogen and oxygen. For a bottle rocket, either in SMALL quantities would pep up your bottles. But then again, a tincture too much and they could go bang. Also you could damage your tympanic membranes permanently.
One mistake and all the fun is over.
Mark

[Mark]

As far as the tri-iodide crystals I have made ammonium tri-iodide crystals, and they are a lot of fun. Super simple to make, you just have to be respectful, and use them right after you make them. DO NOT STORE THEM, or make batches grater than 100g..[/quote]

100 grams of tri-iodide is way too much to be making. I read in a college chemistry book where some wet tri-iodide was set off accidentally in a flask, even before it dried. A bad accident but a good thing to keep in mind. I've made it several times, but would not want to be near ~3 ounces of it, again, that much would blast your eardrums and it is a high explosive of course.
http://jchemed.chem.wisc.edu/JCESoft/CC ... I3IOD.html
http://www.armory.com/~spcecdt/pyrotech/ni3_dir.html
http://www.absoluteastronomy.com/encycl ... iodide.htm
http://mailer.uwf.edu/listserv/wa.exe?A ... =1&P=32484

[Anders Troberg]

Do you know how may Amps DC you were running?

Sorry, no idea. I used a 100 W light bulb to limit the current, and it was not as bright as if connected directly, but still quite bright.

So you used diodes to take the top half of the AC sign wave, were you still running 220V DC in the end?

No, I used a full four diode bridge to invert the negative half of the wave. Thsi probably means that it was less than 220V used, probably in the vicinity of 110V.

Also you were just using plain water? I find that hard to believe. When I have tried it with regular water, it is practically like an insulator. Maybe your water is treated, thus it has mineral salts added, but pure water WILL NOT go though electrolysis.

It's a long time ago, and there was two of us playing with it, so I don't remember all details. I think we have a fairly high amount of calcium in the water, and my friend who is more into chemistry (I focused on the electrical part) may have added something.

I think the speed at which electrolysis takes place is more dependant on the number of amps, not volts you are pushing. Higher amps faster results maybe?

Very possible, but it is easier to push amps directly from the mains than from a battery, which may explain my results.

[Dang911]

When I made the crystals, I purposely used impure iodine, thus making them a little safer. I myself have never made a batch bigger then 25g, enough for a couple of bangs. When I let them dry, they were stable enough to where they wouldn't go off without throwing a brick on top of them. I don't have any interest in making any that will go off with a feather, way to suicidal.

[El-Kablooey]

DON"T USE THE MAINS!!!!! There is absolutely no reason to put yourself in danger doing this! You can get a hell of alot more amps from a good battery charger than the mains voltage, and do it without killing yourself in the process! 100w (limited by lightbulb) comes out to less than .5 amps... You can pull about 100 amps from 2 modified microwave transformers wired to 110v and stepping down the voltage to 12v. A welder or good battery charger will do the same.

[Anders Troberg]

Which is why I specifically said you should stay well clear of the contraption while it is plugged in.

Besides, it is still much safer than playing around with microwave transformers.

However, I agree that a good batterycharger is probably the best bet if you want to be safe.