Electrolysis - Electrode Materials, Factors Affecting Rate...

[akcapr]

btw, u have fileld a baloon w/ oxygen and hydrogen? is that what u mean by "ballon is 17 in in diameter"

[spamonkey8]

Mhm. I explained that in previous posts. The water got hot enough I was worried it would boil, so I stuck it in a mini ice bath. The balloon is still growing, 19 inches last time I checked. No Smoking allowed!

[akcapr]

how long has it been running?

[drizzt]

arent hydrogen molocules small enough to seep through latex ballon material?

[akcapr]

all seep out eventually- hydrogen will seep slowly but faster than helium

[spamonkey8]

It's been up for about 4 hours and it's still going, but slowly because it's mostly adding pressure. The water is very rusty with some sediment at the bottom due to the stainless steel not working as well as it did yesterday. The ice bath cooled it well enough, but the top is getting hot again (I can shake it up: the bottom is still surprisingly cold). My happy birthday balloon is almost finished!

[akcapr]

hav u tested 2 see how the gas burns that comes out?

[spamonkey8]

Why burning gas fuels is harder than burning liquid fuels:

(and yes I realize liquid fuels have to vaporize first but you get the point)

Like all highly flammable gasses, any available amount combusts rapidly with a pop/whoosh sound and a flash. This is true with Hydrogen. Any quality propane or butane torch has a regulator and then a very tiny hole that's almost invisible. After that, it allows the gas to mix with air and directs it through a filter that surrounds the bulk of the flow with smaller parts so that the main portion will remain lit. If you have a propane torch on hand, unscrew the end (the very end, past the regulator knob) and look for that tiny hole. If yours is like mine, turn it on and try to light it. You'll find that just because the gas is coming out doesn't mean it will light. Not only is there no uniform mixture with air, but the pressure keeps the flame from burning down to where the gas is coming out. It's like trying to light the assembled torch from 3 inches away. Yes the gas will burn, but it won't stay lit.

 

In short, Hydrogen gas would rather explode than burn slowly, so you have to force it by shaping the flame, controlling its mix with oxygen, and regulating the flow.

 

I'd like to connect the balloon to that propane torch head and try to light it. I'll get back to you on that.

 

I think that by far the two biggest problems will be these:

 

• Optimizing the conditions of the electrolysis enough to produce a decent amount of product. If I can get a mole of H₂ every hour or two, I would have plenty for a decent flame. This may mean obtaining an industrial power supply and/or selling my soul.

 

• Getting the flame to burn consistently.

 

Electrodes Update:

As a side note, I remembered that the spark plugs in my car are platinum, and I checked to see if I had the old ones laying around, so I have 4 little pieces of platinum to play with, though I'm not sure if it will matter. In those 4 hours of use, an inch-long length of stainless steel wire worked relatively well, only really wearing down to 1/2 its previous size. The wire at the cathode was just fine, so if I can get enough surface area out of platinum for the anode, I'll be able to get this working without spending exorbitant amounts of money and waiting for shipping.

[spamonkey8]

I just had a near-death experience. My ears are ringing, it sounded like a shotgun going off.

 

So I had the balloon with Hydrogen and Oxygen gas in it in the perfect ratio to combust. Highly explosive. I went out to my garage with this balloon. I attached it to a propane torch head and opened up the regulator. I lit a cigarette lighter and held it up to the business end like I was lighting propane. So pretty much it was a balloon replacing the propane tank. A couple little pops showed me that it was coming out (igniting little pockets of it), and then the fun started. A leak at the connection sprung somehow and the entire balloon blew up in my face. I was leaning over at the time, and it singed off some of the hair on my leg.

 

So remember, kids. Next time you are about to try to light a balloon full of a perfectly stochiometrically balanced explosive (the most explosive known), either get a flashback arrestor or tape the damn seal better.

 

Next time, I'm just putting H₂ in it, and in much smaller quantities for damn sure.

 

This warrants a link from the 'stupidest thing you've ever done' thread.

[akcapr]

are u fuc*&%$ kidding me ?!!?! are u retarded? u actually did that!! i should have warned you. Did u not realize the oxygen i nthe mix would cause the flame to go back in?!?!!?! well.... go run it for a few more hours and fill up a nother ballon but be careful. if u do it again it will be fine, just dont light the damn thing with a torch!

[spamonkey8]

No, I'm not retarded and no it didn't go back in. I was crimping the balloon so that only some of it was exposed when I was trying to light it. I wasn't trying to light it when it popped. I was just giving up. The regulator was closed and a leak at the seam was what blew it up.

[akcapr]

eh... u still shouldnt have tried that- not really any point

[spamonkey8]

I have one last question for you guys:

 

If the water is heated up to the boiling point, would water vapor be emitted, or would it just perform steam electrolysis? (http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q=%22Steam+electrolysis%22%3A).

[spamonkey8]

Depending on certain factors, such as the relation between amperage drawn and electrode size, more or less water vapor is produced.

 

As a side note, anyone who recommended sulfuric acid should be shot. It produces hydrogen sulfide gas when it electrolyzes. Not only is it a pollutant, but it is so because once it hits water, it turns back into sulfuric acid, say on the inside of your lungs.

 

NaHCO₃ (baking soda) produces some CO₂ I think

 

NaOH and KOH Simply produce a little sodium or potassium deposits on the bottom. However, both are a bit caustic compared to baking soda. So I'd say, baking soda for test runs and once you're sure it won't spring a leak and spray pressurized electrolytic fluid on you, you can switch to caustic lye (NaOH).

 

Just in case anyone still cares.

[raivo]

As a side note' date=' anyone who recommended sulfuric acid should be shot. It produces hydrogen sulfide gas when it electrolyzes. [/quote']

 

Sulfuric acid electrolysis will never release H2S (expect in case you use sulfides as material for electrodes or container). Sulfuric acid is quite common for water electrolysis, only minus being stability of anode. Thats why NaOH is preferred.

 

When using VERY strong currents with H2SO4 you may get some gaseous sulfur oxides and peroxyacids as byproducts but no H2S.