thermite won't ignite

[latentheat]

Here's a picture of the electrolytic method I described above for making rust...

 

 

I took that about 5 minutes after applying the voltage. The outlet allows me to easily exchange anode and cathode materials for different experiments.

[weldermanx]

what kinda worries me is why you need thermite..... i mean its fun on the fourth but thermites still a bit dangerous...

[akcapr]

is that ac current? if it ac it shouldnt be able to split water and also make rust. i thought it had to be dc.

[EL]

AC is an alternating DC.

[latentheat]

is that ac current? if it ac it shouldnt be able to split water and also make rust. i thought it had to be dc.

 

No it's DC. I'm just using the outlet because the screws are convenient to change up the anode and cathode for different experiments.

 

Just out of the range of that picture on the right is the rectifier/transformer.

[d22k]

AC is an alternating DC.

 

uhuh, but that means u get both both electrodes are and anode and cathode, albeit at several hundred Hz ( i think) so it would be useless for making "rust, because you would also make "rust acid", or at least thats my understanding.

[latentheat]

uhuh, but that means u get both both electrodes are and anode and cathode, albeit at several hundred Hz ( i think) so it would be useless for making "rust, because you would also make "rust acid", or at least thats my understanding.

 

In the united states alternating current is 60 Hz, in europe it's 50 Hz.

 

If you use AC, I don't think anything will happen at all beside gas release and possibly you dissolving your electrodes into a pile of mush.

 

Converting ac to dc is easy tho...all you need is a diode. A diode only allows current to flow in one direction, cutting off the side of the sine wave where y < 0. Y= voltage in this situation. Boom, instant DC. It won't be a steady voltage, but it will always be positive and current will flow in only one direction.

 

You also need a transformer, because you have to lower the voltage to a reasonable level for electrochemistry. 120 v is overkill.

 

I tried my best to draw this diagram freehand on a computer, and it came out sort of ok I guess....

 

 

Can I ask what the heck rust acid is? If you were to use the iron as the cathode on accident, you wouldn't get iron combined with anything. It wouldn't be oxidized into solution.

[akcapr]

i think rust acid is just iron hydroxide, not quite an acid

[EL]

Ferric oxide is a very cheep brownish-dark-red powder found at every painters' shop.

If you insist on making it at home for fun, then a dilute solution of NaCl will do with two electrodes of soft Iron carpenters' nails. As {latentheat} explained, but use AC such that NaOH accumulates at both electrodes to catch the ferric chloride and precipitate it as it forms.

Now here is your entertainment quiz of tonight:

What gas or gases, if any shall be liberated in this process (Hint choices:, Chlorine, Oxygen, Hydrogen, Nitrogen, Methane) What?

[akcapr]

wat the hell? nice quiz ud have to be retarded to not know that h2, o2, and cl2 is liberated.

[latentheat]

Only hydrogen.

 

Chlorine isn't released because the electrode is a reactive metal and loses electrons rather than the chloride ions. This is why iron chloride forms. Oxygen isn't released because it reacts with the iron electrode. Nitrogen and methane are not possible because there was no nitrogen or carbon to begin with in this setup.

[EL]

akcapr, Noooooooooooooooooooooooooooo.

[latentheat]

Noooooooooooooooooooooooooooo.

 

Is this a good or a bad no? And who is it directed at

[akcapr]

im sure chlorine is relesed and so is oxygen. its not like no gas comes of one of the electrodes.

[EL]

Sorry {latentheat} You must have hit the submit button right before me on the edge of the minute.

I had to edit my post to make clear to whom it was directed.

akcapr, the quiz was much easier than you think.

If the the electrodes were not corrodible, water would have been electrolysed.

So you should never "expect" any gasses other than Oxygen and Hydrogen.

So what happens!

NaCl must be retained in the solution.

Your final product is Ferric hydroxide, Fe(OH)3

Where from do you think iron got three hydroxide groups, .....water.

Then hydrogen must be liberated for logical balance.

Using AC will generate hydrogen at both electrodes.

The ionic polarisation of water causes the generation of NaOH at one end and HCl at the other and hydrogen gas escapes at the first while iron is oxidized at the second, but HCl is right there, hence water and FeCl3 will form; On the second half of the cycle, NaOH forms right beside FeCl3 and the exchange takes place; Then the proces repeat untill iron is depleted.

 

Even if the electrodes were platinum, chlorine would never form the gas state but HCL, that is how Oxygen is liberated in water electrolysis.

 

The AC mode is more efficient than the DC mode for producing Fe(OH)3 because ions do not need to travel in solution.

[latentheat]

The AC mode is more efficient than the DC mode for producing Fe(OH)3 because ions do not need to travel in solution.

 

It never even crossed my mind two use 2 iron electrodes with alternating current. Thanks for the cool idea.

[EL]

You are always welcome, latentheat.

[ffsjoe]

I just got my iron oxide from rusting cars that have been stolen and dumped in the bush. An endless supply of many kilos of the stuff. I believe it's Fe3O4 because it is very dark brown/almost black.

[ThermiteMan]

Fe2O3 can be black or dark brown at times as well.

And, "Rust" is Fe2O3

[calbiterol]

And Iron (III) oxide doesn't work for thermite reactions, IIRC.

[ffsjoe]

How could I determine whether it is Fe2O3 or Fe3O4?

[latentheat]

How could I determine whether it is Fe2O3 or Fe3O4?

 

Fe3O4 will stick to a magnet. That's why it's called magnetite.

 

Iron (III) oxide will work, just not as well as magnetite.

[BenSon]

And Iron (III) oxide doesn't work for thermite reactions, IIRC

For FerroAluminium thermites Iron (III) oxide is used (Fe2O3)

Iron (III) oxide will work, just not as well as magnetite.

I'd bet that Fe2O3 would produce more heat then Fe3O4

 

~Scott

[rthmjohn]

I ordered some reagent grade Fe2O3 and was finally successful! Yipee! All i used was Mg ribbon. btw, where can I get some ether to dissolve my homemade rust? It's sorta brown and the ACS grade stuff i ordered is deep red orange. I guess my homemade rust has a lot of carbon impurity.

[rthmjohn]

By the way, thanks for all of your outstanding help YT, Jdurg, and all of you great chemists who replied to this thread. Maybe someday I'll be as knowledgeable as you guys.