AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
Aluminum + NaOCl + Vinegar + Sunlight = Boom
This is an interesting energentic experiment I may get around to trying.
Basis: The action of Hypochlorous acid on Aluminum (also Iron) is reported to produce (slowly) H2 and Cl2 (see http://www.rexresearch.com/scragg/scragg.htm ). The latter, in the presence of strong sunlight/LED, is reported to produce an explosion, the
magnitude of which has been desribed as 5 times that of H2 and O2 (see http://chemistry.proteincrystallography.org/article176.html and demo at http://www.ecobabble.com/hydrogen-and-chlorine-reaction/ ). Warning, this is one big boom from my personal observation with a slightly oversized
hydrogen and oxygen explosion as a kid. Interestingly, per Wikipedia (link: http://en.wikipedia.org/wiki/Hydrogen ), notes that "Hydrogen can react spontaneously and violently at room temperature with chlorine and fluorine
to form the corresponding hydrogen halides", so caution should be exercised. For a safe lab procedure on the H2/Cl2 photo sensitive lab reaction see
http://www.rsc.org/Education/EiC/issues/2009Nov/ExhibitionCh... .
Step 1. Add vinegar (dilute Acetic acid) to Chlorine bleach (NaOCl, Na2CO3, NaCl, NaoH,..) forming dilute Hypochlorous acid (HOCl):
NaOCl + HAc --> NaAc + HOCl
Step 2. Combine in a partially compressed plastic vessel (to allow for gas expansion) Aluminum foil and the HOCl from Step 1. Screw on the cap
tightly. Place in the dark outside.
As to the chemistry, hydrogen is from the reaction of unprotective Aluminum (the Al2O3 layer weaken with drop in pH) and water:
2 Al + 6 H2O --> 2 Al(OH)3 + 3 H2
The Chlorine is most likely from the reaction of decomposed HOCl as follows:
HOCl --> HCl + O
HCl + HOCl --> Cl2 + H2O
Optionally, to promote the formation of Chlorine from HOCl and excess NaOCl, add CaCl2 (or CaCl2 + MgSO4 forming MgCl2) and NaCl. This is a so called
chloride system used in hydrometallury to promote the activity of weak acids, see Hydrometallurgy in Extraction Processes, Vol I, by C. K. Gupta and
T. K. Mukherjee, page 15 at
http://books.google.com/books?id=F7p7W1rykpwC&pg=PA203&lpg=PA203&dq=FeCl2+%2B+O2+%3D+FeO(OH)+%2B+FeCl3&source=bl&ots=fiWLs05y8f&am
p;sig=mi-pV94woVj7JABKBB
zLZcqbEwM&hl=en&sa=X&ei=ZQgfUeq7BIi50AGynoDoBQ&sqi=2&ved=0CFAQ6AEwBA#v=snippet&q=Magnesium%20chloride%20MgCl2&f=false .
The action of MgSO4 on an excess of NaOCl and added NaCl is also noted to form Cl2 per Patent 4,380,533 as a side product of the formation of Dibasic
magnesium hypochlorite (see http://www.google.com/patents/US4380533?printsec=description... .
Step 3. In a day or so, noticeable gas formation should occurred. Half wrap its exterior in reflective Aluminum foil to promote the reaction with
light. As a possible detonation will occur at some point during daylight, the area and vicinity should be prepared.
I would recommend trying this first on a small scale to gauge the power of the explosion. Remember, increasing the volume of gases by 2 could cube the
results (that is, an explosion 8 times more powerful). As previously noted, this reaction is reported to be 5 times more energetic than with hydrogen
and oxygen, so be mindful on scale to avoid injury and destruction of property (see http://www.youtube.com/watch?v=S0eKJZKfMBg ).
Note, there are, of course, other paths presented on this forum for generating H2 and Cl2 that could be employed for a more rapid demonstration of the
reaction of these gases in strong sunlight (or upon heating or exposure to spark).
Note, the enthalpy of combustion for hydrogen in O2 is −286 kJ/mol versus -95 for H2 in Cl2, however, the kinetics in terms of mechanical energy
appear to be quite different with plasma (mixture of ions and electrons) being produced in the explosion.
[EDIT] Please note that one of the educational links provided above suggests using HCl and NaClO3 to produce Chlorine. Bad idea as with the wrong
reactant ratios, ClO2 (a very explosive gas) and Cl2 can be formed. See this link (https://docs.google.com/viewer?a=v&q=cache:3wp90wxOqSMJ:... ) with the listed reaction:
2 NaClO3 + 4.8 HCl → 1.8 ClO2 + 2 NaCl + 2.4 H2O + 1.5 Cl2
[Edited on 26-2-2013 by AJKOER]
|
|
|
KonkreteRocketry
Hazard to Others
Posts: 165
Registered: 12-11-2012
Location: Dubai
Member Is Offline
Mood: No Mood
|
|
wow thats cool, is that ur you tube account ?
|
|
|
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
No, not my youtube, but, I agree, cool.
Note, the ignition is intended to be by the light from the burning Magnesium ribbon (very dramatic but using a small uv LED light is less dangerous
and expensive), but perhaps contact with the burning ribbon (note thermal detonation at 500 C) may have actually took place instead.
--------------------------------------------------------
An obvious criticism of my suggested design is that it is difficult to estimate whether one has the most effective 50/5O balance of H2 and Cl2. Even
with precise amounts and a complete understanding of the reaction scheme, some of the Cl2 may be dissolved in (or lost to) the solution. However,
there is a very wide ratio on the gases for this reaction that result in an explosion, so expect a detonation. One source (http://jes.ecsdl.org/content/101/12/626.abstract ) states that the lower explosive limit varies from about 3.1% to 8.1% hydrogen depending on
pressure and chlorine concentration in a gas mix of oxygen, nitrogen, and carbon dioxide.
Independent generation of the precise amounts of H2 and Cl2 may help, but there is still the mixing operation where a very light H2 gas will readily
escape, while the very heavy Cl2 remains behind.
[Edited on 26-2-2013 by AJKOER]
|
|
|
Ozone
International Hazard
Posts: 1269
Registered: 28-7-2005
Location: Good Olde USA
Member Is Offline
Mood: Integrated
|
|
Ah yes, http://books.google.com/books?id=IDEFAAAAQAAJ&pg=PA119&a...
A really cool demo involved a stoichiometric mix of H2 and Cl2 in a glass globe. When shown in front of a red glass window, nothing occurred. When the
window was switched to blue, the expected reaction occurred and boom.
Nice one,
O3
-Anyone who never made a mistake never tried anything new.
--Albert Einstein
|
|
|
AndersHoveland
Hazard to Other Members, due to repeated speculation and posting of untested highly dangerous procedures!
Posts: 1986
Registered: 2-3-2011
Member Is Offline
Mood: No Mood
|
|
It is very rare that the reactions within a single solution can produce both an oxidizing gas and a flammable gas. Obviously such a reaction has
implications for producing explosive gas mixtures inside bottles, for fun, novelty, and educational demonstrations.
I described another such reaction in the thread "Producing Hydrogen by partial oxidation",
http://www.sciencemadness.org/talk/viewthread.php?tid=18169
I'm not saying let's go kill all the stupid people...I'm just saying lets remove all the warning labels and let the problem sort itself out.
|
|
|
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
Actually, the H2/Cl2 kinetic reaction is a bit more than a novelty. The link http://www.rexresearch.com/scragg/scragg.htm discusses working engines that are completely self-sustained. Perhaps some government (foreign most
likely) will put money in to develop the concept.
In my opinion, the authors' are a bit naive if they think anything is going to happen in America. Who is going to back the concept? Not car companies
pushing carbon based fuels (gasoline or natural gas or gas/electric) or pure electric or fuel cell, and certainly not the battery manufacturers. Wait,
maybe it will be the big oil companies and the refineries, who own all those gas stations (obsolete) who want to sell you gas (obsolete) or an
electric charge for your battery (obsolete)? And for the last possible investor, the broken US government run largely for the interest of current
lobbyists, no way. Just be thankful that our cars are not steam engines burning coal, and we all can take a breath absent a gas mask.
What the authors should be doing as they have constructed their engines from largely off the shelf parts is put together necessary specialty parts for
sale and instructions so that we can all start constructing (or hire skilled machinists) to build our own cars! Now that would be a car revolution!
[Edited on 27-2-2013 by AJKOER]
|
|
|
Fantasma4500
International Hazard
Posts: 1681
Registered: 12-12-2012
Location: Dysrope (aka europe)
Member Is Offline
Mood: dangerously practical
|
|
i have seen something that might be of interest aswell..
i remember it as alcohol of some sort (ethanol??) in a bottle along with hydrogen peroxide (3-6%??) and perhaps it was bleach that made the reaction
start up? perhaps MnO2?
anyways what this reaction should yield was a loudly exploding gas mixture of the corresponding alcohol gas vapour + O2 from the decomposed H2O2
i have never tried it myself, but i like the idea as acetone or even ether could be used! and also... .. perhaps this could even be made with hydrogen
as in NaOH + Al + H2O2 + MnO2
perhaps even HCl + Al + H2O2
HCl + Al = H2
H2O2 + HCl as ive observed it creates Cl or well something that smells alike, 10% makes some sort of decomposition, anyhow..
so a relatively random mixup of ethanol, HCl, zinc metal (for easier etching), H2O2 and MnO2 should give some results but not selfigniting, hopefully
|
|
|
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
Antiswat:
Be careful in mixing so many ingredients together! Serious concerns on " a relatively random mixup of ethanol, HCl, zinc metal (for easier etching),
H2O2 and MnO2 should give some results but not self igniting, hopefully"
One possible reaction sequence could form some Ethyl hypochlorite (see http://www.sciencemadness.org/talk/viewthread.php?tid=1896 for more details and stability/energetic properties):
MnO2 + 4 HCl --> MnCl2 + Cl2 + 2 H2O
2 HCl (dilute) + H2O2 --> 2 HOCl
2 HCl + H2O2 --> Cl2 + 2 H2O <--> HCl + HOCl + H2O
C2H5OH + HOCl --acid-> C2H5ClO + H2O
Zn + 2 HCl --> ZnCl2 + H2
Now, assuming that any Ethyl hypochlorite is formed (function of HOCl strength) and successfully separates before the Hydrogen and the Chlorine
undergo a photo initiated explosion, is one scenario that could produce quite a fireball combined with a highly kinetic explosion (very dangerous,
perhaps with a semi-similarity to a thermobaric detonation). A major risk factor here is many alcohol based hypochlorites are generally viewed as
having stability issues. Methyl hypochlorite, for example, is so bad tempered it could explode for no apparent reason (perhaps you stared it too
long). Ethyl hypochlorite is a bit better and has been described as "a flammable liquid, though explodes when confined" by Axt in the referenced
thread, others, perhaps with more concentrated solutions, less favorably. To quote: "The substance is highly unstable, decomposing at room
temperature; In direct sunlight the heat of decomposition is sufficient to cause vigorious boiling, soon followedl by explosion of the vapors" (see http://thesis.library.caltech.edu/1508/1/Ellis_el_1932.pdf ).
Of additional concern to me is that with excess NaOCl/HOCl, more products can be formed. Bottom line, I am not very comfortable with the known
possible products, and given the characteristic of a possible H2/Cl2/C2H5ClO explosion, I would avoid this experiment.
-------------------------------------------------------------------------
Interestingly, for those interested in thermobaric explosives, note per Wikipedia (http://en.wikipedia.org/wiki/Ethylene_oxide ):
"With a high yield (90%) ethylene oxide can be produced by reacting calcium oxide with ethyl hypochlorite; substituting calcium by other alkaline
earth metals reduces the reaction yield:[52]
2 CH3CH2–OCl + CaO → 2 (CH2CH2)O + CaCl2 + H2O "
where ethylene oxide is described by Wikipedia as "a very hazardous substance: at room temperature it is a flammable, carcinogenic, mutagenic,
irritating, and anaesthetic gas with a misleadingly pleasant aroma", and also "is extremely flammable and explosive and is used as a main component of
thermobaric weapons;[2][3] therefore, it is commonly handled and shipped as a refrigerated liquid.[4]". Yelp, excuse me if I avoid making this one
too.
[Edited on 5-3-2013 by AJKOER]
|
|
|
AJKOER
Radically Dubious
Posts: 3026
Registered: 7-5-2011
Member Is Offline
Mood: No Mood
|
|
Quote: Originally posted by AJKOER  | This is an interesting energentic experiment I may get around to trying.
Basis: The action of Hypochlorous acid on Aluminum (also Iron) is reported to produce (slowly) H2 and Cl2 (see http://www.rexresearch.com/scragg/scragg.htm ). The latter, in the presence of strong sunlight/LED, is reported to produce an explosion, the
magnitude of which has been desribed as 5 times that of H2 and O2 (see http://chemistry.proteincrystallography.org/article176.html and demo at http://www.ecobabble.com/hydrogen-and-chlorine-reaction/ ). Warning, this is one big boom from my personal observation with a slightly oversized
hydrogen and oxygen explosion as a kid. Interestingly, per Wikipedia (link: http://en.wikipedia.org/wiki/Hydrogen ), notes that "Hydrogen can react spontaneously and violently at room temperature with chlorine and fluorine
to form the corresponding hydrogen halides", so caution should be exercised. For a safe lab procedure on the H2/Cl2 photo sensitive lab reaction see
http://www.rsc.org/Education/EiC/issues/2009Nov/ExhibitionCh... .
Step 1. Add vinegar (dilute Acetic acid) to Chlorine bleach (NaOCl, Na2CO3, NaCl, NaoH,..) forming dilute Hypochlorous acid (HOCl):
NaOCl + HAc --> NaAc + HOCl
Step 2. Combine in a partially compressed plastic vessel (to allow for gas expansion) Aluminum foil and the HOCl from Step 1. Screw on the cap
tightly. Place in the dark outside.
As to the chemistry, hydrogen is from the reaction of unprotective Aluminum (the Al2O3 layer weaken with drop in pH) and water:
2 Al + 6 H2O --> 2 Al(OH)3 + 3 H2
The Chlorine is most likely from the reaction of decomposed HOCl as follows:
HOCl --> HCl + O
HCl + HOCl --> Cl2 + H2O
....
|
I have performed Step1 and Step 2. After a few days of observation of the solution in sunlight, I must report that the chemistry is a bit off. Yes,
the formation of Al(OH)3 like clear precipitate. However, no Cl2 and the gas formation is more likely H2 and, after all the Aluminum was consumed,
still some gas formation, most likely O2, I suspect.
I added NaHSO4 to test whether the resulting mixture was Aluminum hypochlorite as it would then liberate Cl2 if true. Instead, a white cake-like
precipitate was formed. After some research, I identified it as Basic aluminum sulfate, which is formed upon the addition of NaHSO4 to a basic
Aluminum salt. This means the solution could have been Basic Aluminum chloride (most likely given the relative small Chlorine scent and the evident
consumption of Cl2), or a Basic Aluminum oxychloride or similar double acetate salt.
If any Cl2 is formed, it is readily consumed. Any O2 formation could have been produced from the decomposition of HOCl or from the breakdown of any
Aluminum hypochlorite that happened to be created.
This was a relatively simple experiment, but yet the Chemistry can get complex.
[Edited on 6-3-2013 by AJKOER]
|
|
|
Adas
National Hazard
Posts: 711
Registered: 21-9-2011
Location: Slovakia
Member Is Offline
Mood: Sensitive to shock and friction
|
|
It would be good to substitute NaOCl by Ca(OCl)2, because NaOCl solutions are very dilute, and you can buy 70% Ca(OCl)2 without
a problem.
I will definitely try this one soon. 
Rest In Pieces!
|
|
|
|
![[*]](images/xpblue/default_icon.gif){kind=icon}
