Gallium + Aluminum = hydrogen Gas
EEYORE, Thu May 24 2007, 04:23AMHello all,
im back from a very long hiatus. Calculus has been killer (Im terrible at math) but made it to calc 2...
Anyways, I caught word of an experiment done with Gallium metal and Aluminum metal that produces hydrogen gas. Any thoughts on this?Is it as simple as putting some gallium metal onto an Aluminum heatsink and throwing into some water?
Matt
Re: Gallium + Aluminum = hydrogen Gas
Shaun, Thu May 24 2007, 06:50AM
This is a common experiment done with gallium (not so common). A drop of liquid gallium, it has a very low melting point, is dripped onto aluminum foil. Gallium forms alloys very well, and eats through the AL foil in seconds. What you are left with is a glob of gallium with aluminum dissolved in it. In this state, Aluminum is far more reactive than normal (dissolved things usually are), and if water is dripped on to the mass you will get a sodium-esque reaction, forming aluminum hydroxide, hydrogen gas, and water. The gallium does not react.
Don't get too carried away if you have a chance to do this. Gallium is pretty expensive.
It's explained better here, see the bottom of the page.
Shaun, Thu May 24 2007, 06:50AM
This is a common experiment done with gallium (not so common). A drop of liquid gallium, it has a very low melting point, is dripped onto aluminum foil. Gallium forms alloys very well, and eats through the AL foil in seconds. What you are left with is a glob of gallium with aluminum dissolved in it. In this state, Aluminum is far more reactive than normal (dissolved things usually are), and if water is dripped on to the mass you will get a sodium-esque reaction, forming aluminum hydroxide, hydrogen gas, and water. The gallium does not react.
Don't get too carried away if you have a chance to do this. Gallium is pretty expensive.
It's explained better here, see the bottom of the page.
Re: Gallium + Aluminum = hydrogen Gas
EEYORE, Thu May 24 2007, 03:51PM
So it does sound pretty simple...I can get 10g of gallium for about 23$. Good deal?About how much H2 gas is produced?How would the volume of gas relate to say, throwing Al foil into some Hydrochloric Acid?
Matt
EEYORE, Thu May 24 2007, 03:51PM
Shaun wrote ...
This is a common experiment done with gallium (not so common). A drop of liquid gallium, it has a very low melting point, is dripped onto aluminum foil. Gallium forms alloys very well, and eats through the AL foil in seconds. What you are left with is a glob of gallium with aluminum dissolved in it. In this state, Aluminum is far more reactive than normal (dissolved things usually are), and if water is dripped on to the mass you will get a sodium-esque reaction, forming aluminum hydroxide, hydrogen gas, and water. The gallium does not react.
Don't get too carried away if you have a chance to do this. Gallium is pretty expensive.
It's explained better here, see the bottom of the page.
This is a common experiment done with gallium (not so common). A drop of liquid gallium, it has a very low melting point, is dripped onto aluminum foil. Gallium forms alloys very well, and eats through the AL foil in seconds. What you are left with is a glob of gallium with aluminum dissolved in it. In this state, Aluminum is far more reactive than normal (dissolved things usually are), and if water is dripped on to the mass you will get a sodium-esque reaction, forming aluminum hydroxide, hydrogen gas, and water. The gallium does not react.
Don't get too carried away if you have a chance to do this. Gallium is pretty expensive.
It's explained better here, see the bottom of the page.
So it does sound pretty simple...I can get 10g of gallium for about 23$. Good deal?About how much H2 gas is produced?How would the volume of gas relate to say, throwing Al foil into some Hydrochloric Acid?
Matt
Re: Gallium + Aluminum = hydrogen Gas
Wolfram, Thu May 24 2007, 03:59PM
I'm not too sure about this, but I'd think that the amount of hydrogen produced should be approximately equal for a given amount of aluminium.
This seems like a bad and expensive way of making hydrogen to me. Unless hydrocloric acid and lye are unreasonably expensive where you live, I don't see how this way has any advantage. There are very many good ways of generating hydrogen, and this is not one of them. The gallium could propably be recovered with some effort, but considering the effort and the lost gallium, it would be a very expensive way of getting hydrogen.
Wolfram, Thu May 24 2007, 03:59PM
I'm not too sure about this, but I'd think that the amount of hydrogen produced should be approximately equal for a given amount of aluminium.
This seems like a bad and expensive way of making hydrogen to me. Unless hydrocloric acid and lye are unreasonably expensive where you live, I don't see how this way has any advantage. There are very many good ways of generating hydrogen, and this is not one of them. The gallium could propably be recovered with some effort, but considering the effort and the lost gallium, it would be a very expensive way of getting hydrogen.
Re: Gallium + Aluminum = hydrogen Gas
Shaun, Thu May 24 2007, 11:14PM
That's true. I mean, theoretically, if you set aside a few grams of gallium specifically for use in the H2 generator, you could just continue to add and react more aluminum, provided you are willing to remove the Al(OH)3 after each use, because the gallium is essentially a catalyst. I dont know how you could go about this, because even though gallium could be made liquid and the Al(OH)3 would be solid, something tells me gallium wont go through a piece of filter paper.
If it is just the H2 you're after, try these:
Al foil and drano (NaOH solution)
Al foil and Muriatic Acid- this one's best for balloon filling
Electrolysis of NaCl solution (or any other salt, as long as you have a graphite anode)
*this one is very slow
Shaun, Thu May 24 2007, 11:14PM
That's true. I mean, theoretically, if you set aside a few grams of gallium specifically for use in the H2 generator, you could just continue to add and react more aluminum, provided you are willing to remove the Al(OH)3 after each use, because the gallium is essentially a catalyst. I dont know how you could go about this, because even though gallium could be made liquid and the Al(OH)3 would be solid, something tells me gallium wont go through a piece of filter paper.
If it is just the H2 you're after, try these:
Al foil and drano (NaOH solution)
Al foil and Muriatic Acid- this one's best for balloon filling
Electrolysis of NaCl solution (or any other salt, as long as you have a graphite anode)
*this one is very slow
Re: Gallium + Aluminum = hydrogen Gas
Bored Chemist, Fri May 25 2007, 05:50AM
The yield of H2 is exactly the same. Gallium ought to act as a catalyst but I think the impurities in the foil would mess it up eventually.
Bored Chemist, Fri May 25 2007, 05:50AM
The yield of H2 is exactly the same. Gallium ought to act as a catalyst but I think the impurities in the foil would mess it up eventually.
Re: Gallium + Aluminum = hydrogen Gas
badastronaut, Fri May 25 2007, 06:27PM
badastronaut, Fri May 25 2007, 06:27PM
Re: Gallium + Aluminum = hydrogen Gas
Bored Chemist, Sat May 26 2007, 08:47AM
That reaction is not new. Gallium has been bannd from air transport for years because of it (as has mercury).
Bored Chemist, Sat May 26 2007, 08:47AM
That reaction is not new. Gallium has been bannd from air transport for years because of it (as has mercury).
Re: Gallium + Aluminum = hydrogen Gas
EEYORE, Mon May 28 2007, 05:49AM
My main interest in this as opposed to HCL + Al. was that HCL is dangerous whereas Gallium is not. How hard would the separation of Al. Hydroxide from the Gallium be?I may get some Gallium and give it a try, unless this is just going to be too much of a pain to do.
Thanks for your insight!
Matt
EEYORE, Mon May 28 2007, 05:49AM
My main interest in this as opposed to HCL + Al. was that HCL is dangerous whereas Gallium is not. How hard would the separation of Al. Hydroxide from the Gallium be?I may get some Gallium and give it a try, unless this is just going to be too much of a pain to do.
Thanks for your insight!
Matt
Re: Gallium + Aluminum = hydrogen Gas
Shaun, Wed May 30 2007, 11:18PM
Well, given that Al(OH)3 is a solid and Gallium can be heated to a liquid, I would say that maybe a simple filter would do it. Gallium, even when liquid, will probably have way too much surface tension to go thru the filter (mercury sure does). You would also probably lose some gallium as it is absorbed in the filter.
Al(OH)3 wouldn't be in solution, so a centrifuge would do a great job separating them. You could spin it for a minute or two, then pour off the gallium. Keep in mind the container will need to be inverted, because gallium is denser than aluminum hydroxide. Most people don't have access to one of these, but just throwing it out there...
I don't what exactly you want out of this reaction, but again if its just the H2, I would say screw the expensive gallium and just go with the HCl+Al. So what if its a little dangerous, you don't even need a high concentration. The HCl you buy is around 12 molar (33%), so just dilute it 5-10 times. 1 or 2 molar will work fine, trust me, and if any gets on you, just wash it off, no big deal. Every Home Depot/Lowes has it, and it's DIRT CHEAP (as opposed to gallium).
This is exactly how my friends and I used to make H2 balloons (7~10 years ago). You can tie them to a bus stop pole with a bogus birthday party sign and people try to pop them with lit cigarettes. It's a miracle we didn't end up in prison, with the crazy shit we did...
Shaun, Wed May 30 2007, 11:18PM
Well, given that Al(OH)3 is a solid and Gallium can be heated to a liquid, I would say that maybe a simple filter would do it. Gallium, even when liquid, will probably have way too much surface tension to go thru the filter (mercury sure does). You would also probably lose some gallium as it is absorbed in the filter.
Al(OH)3 wouldn't be in solution, so a centrifuge would do a great job separating them. You could spin it for a minute or two, then pour off the gallium. Keep in mind the container will need to be inverted, because gallium is denser than aluminum hydroxide. Most people don't have access to one of these, but just throwing it out there...
I don't what exactly you want out of this reaction, but again if its just the H2, I would say screw the expensive gallium and just go with the HCl+Al. So what if its a little dangerous, you don't even need a high concentration. The HCl you buy is around 12 molar (33%), so just dilute it 5-10 times. 1 or 2 molar will work fine, trust me, and if any gets on you, just wash it off, no big deal. Every Home Depot/Lowes has it, and it's DIRT CHEAP (as opposed to gallium).
This is exactly how my friends and I used to make H2 balloons (7~10 years ago). You can tie them to a bus stop pole with a bogus birthday party sign and people try to pop them with lit cigarettes. It's a miracle we didn't end up in prison, with the crazy shit we did...
Re: Gallium + Aluminum = hydrogen Gas
EEYORE, Thu May 31 2007, 06:46PM
Yea, im beginning to side with you against gallium. I guess it was also an excuse to get some gallium...
As to the H2 balloons...Wow that is very funny!Id love to see that happen, that will show those people who have a desire to pop balloons just for destruction...
Matt
EEYORE, Thu May 31 2007, 06:46PM
Yea, im beginning to side with you against gallium. I guess it was also an excuse to get some gallium...
As to the H2 balloons...Wow that is very funny!Id love to see that happen, that will show those people who have a desire to pop balloons just for destruction...
Matt
Re: Gallium + Aluminum = hydrogen Gas
Shaun, Thu May 31 2007, 07:25PM
Don't get me wrong, tho, I would love to have some gallium. A non-toxic metal that melts in your hand? How cool is that?
And you can make alloys with it that melt below room temp, so its like non-toxic mercury substitute. I've always wanted to know what it would feel like to put your hand in a beaker of mercury, if it wasn't poisonous. I bet the weight of the liquid would feel like squeezing your hand.
Sadly, that much gallium would cost hundreds of dollars...
Shaun, Thu May 31 2007, 07:25PM
Don't get me wrong, tho, I would love to have some gallium. A non-toxic metal that melts in your hand? How cool is that?
And you can make alloys with it that melt below room temp, so its like non-toxic mercury substitute. I've always wanted to know what it would feel like to put your hand in a beaker of mercury, if it wasn't poisonous. I bet the weight of the liquid would feel like squeezing your hand.
Sadly, that much gallium would cost hundreds of dollars...
Re: Gallium + Aluminum = hydrogen Gas
Swany, Fri Jun 01 2007, 05:31PM
But you'd be wrong. Gallium is notorious for its lack of surface tension and it's property of sticking to everything, quite unlike Hg! To clear Hg of surface goo, I pour it into a filter paper and it just sits there, well, poke a hole in the paper and the Hg streams through leaving the gunk behind.
Hg's toxicity has been blown out of proportion by the media. I have 3lbs of it 3 feet from me, but that is irrelivent as it is sealed quite happily. It is interesting to stick your hand in it and have it come out perfectly dry. Gallium, on the other hand, would coat your hand with a silvery film and it sticks to beakers and mirrors everything it touches.
Swany, Fri Jun 01 2007, 05:31PM
But you'd be wrong. Gallium is notorious for its lack of surface tension and it's property of sticking to everything, quite unlike Hg! To clear Hg of surface goo, I pour it into a filter paper and it just sits there, well, poke a hole in the paper and the Hg streams through leaving the gunk behind.
Hg's toxicity has been blown out of proportion by the media. I have 3lbs of it 3 feet from me, but that is irrelivent as it is sealed quite happily. It is interesting to stick your hand in it and have it come out perfectly dry. Gallium, on the other hand, would coat your hand with a silvery film and it sticks to beakers and mirrors everything it touches.
Re: Gallium + Aluminum = hydrogen Gas
Shaun, Fri Jul 13 2007, 05:02AM
Right, I know gallium can be used to wet glass to make 1st surface mirrors, so it would probably do the same for a filter paper.
So you actually can safely touch HG? Is that because only the vapor is poisonous (as long as you don't eat the liquid or something...)? I have about 5 grams I got from the old thermometers our chem teacher was gonna throw out, but where can I get 3 pounds? not just for touching, but it would be nice to have.
Could you compare it to the toxicity of solid or liquid lead? Because I know how overblown that is... I should be dead with the amount of lead-based soldering I've done.
Shaun, Fri Jul 13 2007, 05:02AM
Right, I know gallium can be used to wet glass to make 1st surface mirrors, so it would probably do the same for a filter paper.
So you actually can safely touch HG? Is that because only the vapor is poisonous (as long as you don't eat the liquid or something...)? I have about 5 grams I got from the old thermometers our chem teacher was gonna throw out, but where can I get 3 pounds? not just for touching, but it would be nice to have.
Could you compare it to the toxicity of solid or liquid lead? Because I know how overblown that is... I should be dead with the amount of lead-based soldering I've done.
Re: Gallium + Aluminum = hydrogen Gas
Swany, Tue Jul 17 2007, 05:49PM
The toxicities of the two metals are not exactly comparable due to the differing physical traits. Lead vapors and compounds are dangerous, just as mercury's are. However, the bp. of Hg is circa de ~380C wheras lead is 1700C or so. Vapor pressures for both are much different, however both of them are very low at touchy-feely tempartures.
So, mercury is dangerous.... partially true. Once it is absorbed in your bloodstream or stuck in your body yes. Let us go over the possible ways of mercury exposure:
Handling: high surface tension and a barrier of skin implies that it will not be readily absorbed. Stay away from open cuts, but even there the surface tension...
Inhaling: rather difficult to do; the RT metal does not exactly evaporate oh-so-quickly, and the heated metal --well, don't do that.
Ingestion: It literally goes right through you due to density, your body retains about 1%, so I've read. Wouldn't try that.
Just don't eat lead.
Gallium toxicity, never hear anything about that.. some gallium compounds are used medically, Ga (III) behaves as iron in body chemistry, so in theory lots of Ga(III) could do bad things, but it is used as an antibacterial agent for that exact reason.
Swany, Tue Jul 17 2007, 05:49PM
The toxicities of the two metals are not exactly comparable due to the differing physical traits. Lead vapors and compounds are dangerous, just as mercury's are. However, the bp. of Hg is circa de ~380C wheras lead is 1700C or so. Vapor pressures for both are much different, however both of them are very low at touchy-feely tempartures.
So, mercury is dangerous.... partially true. Once it is absorbed in your bloodstream or stuck in your body yes. Let us go over the possible ways of mercury exposure:
Handling: high surface tension and a barrier of skin implies that it will not be readily absorbed. Stay away from open cuts, but even there the surface tension...
Inhaling: rather difficult to do; the RT metal does not exactly evaporate oh-so-quickly, and the heated metal --well, don't do that.
Ingestion: It literally goes right through you due to density, your body retains about 1%, so I've read. Wouldn't try that.
Just don't eat lead.
Gallium toxicity, never hear anything about that.. some gallium compounds are used medically, Ga (III) behaves as iron in body chemistry, so in theory lots of Ga(III) could do bad things, but it is used as an antibacterial agent for that exact reason.
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