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thumbup.gif posted on 5-7-2008 at 04:01
Hypergolic Reactions and Energetics


How about substances that explode on mixing? E.g.:

A mixture of about 90% H2O2 and conc. H2SO4 in a one-to-one volume ratio, in a drop amount will react extremely violently (near explosion) with a drop acetone added producing ignition and shooting the acid. Though drop amounts of either ethanol or ether with the same mixture do not show a reaction.

Ether is said to potentially interact explosively with anhydrous HNO3 (Bretherick’s), conc. HNO3 and ether in presence of conc. H2SO4 are said to explode violently. In the drop amounts, I was able to establish a violent interaction, but no ignition both with brown fuming HNO3 (with a d= 1.52) and this mixed with conc. H2SO4 (1:1 volume).

DMSO is said to react very violently and even explosively with acyl and nonmetal halides (e.g. acetyl chloride, cyanuric chloride, PCl3, S2Cl2, SOCl2, etc), notably oxalyl chloride.

MeOH can oxidize explosively from HNO3 if nitrogen oxides are present. In drop amounts, reddish fuming HNO3 (d = 1.52) added to MeOH showed no visible interaction.

Title Changed, Chemoleo


[Edited on 6-12-2008 by chemoleo]
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[*] posted on 10-7-2008 at 01:17


WW2 german rocket technology used very dangerous hypergolic chemcals as fuels for rocket planes
C-stoff and T-Stoff were the german names of the chems. T-Stoff 90%, Hyd Per/ C-Stoff, Hydrazine Hydrate,methanol,water.

later another rocket engne operating on similar principles used a different mixture 98+ NA oxidizer/Kerosene fuel

[Edited on 10-7-2008 by grndpndr]

[Edited on 10-7-2008 by grndpndr]
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[*] posted on 10-7-2008 at 16:32


T-Stoff was the name for highly concd. H2O2. I have a book on German rockets it’s called Flugkörper und Lenkraketen (1987), they say the optimal concentration of the H2O2 was between 80 to 85%, and the rest water, higher concentrations did give better performance, but were difficult to control, in addition that higher conc. peroxide is an explosion risk and will freeze easily by a light frost. C-Stoff is 57% N2H4 hydrate, 30% methanol and 13% water with the addition of a small amount of potassium cuprocyanide (0.6 g/L). This combination was also used for propulsion of Messerschmitt Me 163 B, but not without some horrible failures.

The reason for the catalyst, because highly concd. H2O2 will not react quickly enough with hydrazine hydrate, unless catalysts are present. But it is said 1,1-dimethylhydrazine reacts more easily. N2H4 itself also tends to ignite from some catalysts and fine material. N2H4 has also found some use as a monopropellant as it burns after being ignited even without an atmosphere of oxygen.

I've read gasoline and HNO3 are hypergolic. A drop of the strong fuming HNO3 added to two drops gasoline only showed an evolution of nitrogen oxides. Kerosene in the same instance just turns dark with the acid, and no gas evolution. More exciting would be observing the reactions of N2H4 with some oxidizers, but it is a hell to make.

[Edited on 10-7-2008 by Schockwave]
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[*] posted on 10-7-2008 at 17:28


N2O4 detonates on mixing with N2H4. and rapidly ignites glyoxime.

To state the obvious Mn2O7 explodes with a bang on contact with xylene.

Sodium nitromethanate (aka sodium methylnitronate) is said to ignite on contact with water, however it won't for me. Though I know it ignites on contact with Cl2.
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[*] posted on 10-7-2008 at 18:50


Mn2O7 explodes on contact with almost any simple organic material as it is itself explosive (shock sensitivity also like Hg-fulminate) and a powerful oxidizer, but even with finely divided materials like Ag2O or MnO2 bring a reaction. Itself it is a weak explosive having a VOD of 400 m/sec. according to Gmelin Mn [C1] p. 366, I could imagine on contact with a fuel it becomes quite powerful.

Plain hypergolic reactions themselves are easier to come by than the stronger reactions. Sodium dichloro-s-triazinetrione in a small powdered pile ignites a drop of DMSO evolving gas and a garlic odor. KMnO4 will also ignite DMSO in those amounts if it is a dust. KMnO4 of 20% in RFNA is said to make the acid immediately hypergolic with the basic alcohols (MeOH, EtOH, etc), but it didn't work in drop amounts by me. KMnO4 ignites also with an array of compounds, notably polyalcohols glycerol, glycol, some brake fluids, etc. though usually with some delay, and it is said to explode with N2H4.

[Edited on 10-7-2008 by Schockwave]
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[*] posted on 11-7-2008 at 16:09


Solid KClO3 and conc H2SO4 should explode upon mixing. I wonder what happens with conc HNO3...
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[*] posted on 11-7-2008 at 19:07


Quote:
Originally posted by vulture
Solid KClO3 and conc H2SO4 should explode upon mixing. I wonder what happens with conc HNO3...


I recall that pyrotechnic mixtures using both a chlorate and a nitrate are generally not used because they are prone to spontaneous unintended detonation. I suspect that would be the case here, probably with the evolution of some particularly enjoyable NO and NOCL varieties.




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[*] posted on 12-7-2008 at 17:57


Quote:
Originally posted by vulture
Solid KClO3 and conc H2SO4 should explode upon mixing.


H2SO4 and KClO3 forms HClO3, which is of course very unstable. The highest concentration of HClO3 which is said to be obtainable and handable is 40%. Higher concentrations decompose to HClO4, ClO2, and Cl2.

A few drops of conc. H2SO4 added to a small pile of KClO3 turned it red and frothed giving off some gases (likley ClO2, Cl2). Dipping in a tissue into this causes snaps and crackles. Adding a few drops of conc. H2SO4 to a larger quantity mixture of KClO3 and sugar or starch, etc. is another well known hypergolic ignition reaction, although it can be a bit more violent than a simple ignition. There are a couple videos on YouTube.

A small KClO3 pile, enough to absorb about 1 drop ethanol ignited and burned violently after 2 drops H2SO4. In the same case but using 2 drops methanol, also a more violent ignition and reaction. Slightly oversaturating a pile of KClO3 with 1 drop glycerin then 2 drops H2SO4 causes frothing and gas evolution, but when the mixture was stirred with a rod, it shot out some flames.One drop acetone absorbed onto a small KClO3 pile quickly having 2 drops H2SO4 added turned red and gave off some gases. A small pile of KClO3 having a few drops DMSO (slight oversaturation) caused a violent ignition and strong burning reaction when the H2SO4 was added. A few drops of ether absorbed onto KClO3 caused immediate ignition as soon as the H2SO4 contacted the mixture. In some of the mixtures, the acid also shoots out. I thought the reactions with methanol could form the dangerous methyl perchlorate which is said to be more brisant than CH3ONO2.

Quote:
I wonder what happens with conc HNO3...


I doubted these would react, and I tried it with a small pile of KClO3 (around 0.1 g) with several drops of reddish fuming HNO3 (d = 1.52), it didn't show any visible reaction or color change as the acid saturated the chlorate, but a tissue dipped into this mixture caused sizzling, charring and sparking evolving a significant volume of gas. Adding several drops methanol to a small pile of KClO3, on the addition of 1 drop of the HNO3 gave an audible pop and set fire to the rest of the methanol.

Quote:
Originally posted by ShadowWarrior4444 I recall that pyrotechnic mixtures using both a chlorate and a nitrate are generally not used because they are prone to spontaneous unintended detonation. I suspect that would be the case here, probably with the evolution of some particularly enjoyable NO and NOCL varieties.


Are you are thinking of nitrate and aluminum powder which can ignite spontaneously (especially when wet)? Maybe also chlorates mentioned here mixed with sulfide or sulfur (especially sulfur flower), which can ignite spontaneously. I think you might actually mean ammonium nitrate together with a chlorate salt, that is a definite spontaneous explosion risk.

[Edited on 13-7-2008 by Schockwave]
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[*] posted on 16-7-2008 at 16:54


This one is more of an ignition. Even though the following will react immediatley and strongly under large gas evolution and sizzling alone, the permanganate was needed for ignition. Adding a drop of turpentine to a drop of the strong fuming HNO3 containing some KMnO4 powder caused a flame to flash out. Reportedly, it is said other catalysts work: FeCl3, CuCl2, oleum, NH4VO3, for turpentine to cause ignition with the fuming acid.

[Edited on 16-7-2008 by Schockwave]
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[*] posted on 17-7-2008 at 05:53


I have heard that turpentine can ignite when exposed to chlorine, is that true?



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[*] posted on 17-7-2008 at 11:51


Quote:
Originally posted by Zinc
I have heard that turpentine can ignite when exposed to chlorine, is that true?


Negative, by my experience. I put a drop of turpentine onto a plastic carrier and lowered it into a graduated cylinder containing a chlorine generator of conc. HCl and KMnO4, and the drop didn't ignite. I also generated some Cl2 in a bottle and poured it out into a dish containing a few drops turpentine, and again no reaction. Here it's said to be able to ignite it, maybe then in a warm reaction condition, or larger amounts and allowing it to sit for a bit.

But I've also tried different chlorinating compounds. No reaction of turpentine with powdered pile of sodium dichloro-s-triazinetrione. A chlorinator containing: 1-bromo-3-chloro-5,5-dimethylhydantoin (60%), 1,3-dichloro-5,5-dimethylhydantoin (27.4%), 1,3-dichloro-5-ethyl-5-methylhydantoin (10.6%) and the rest inert. A powdered pile of this with a few drops turpentine absorbed after a few short seconds made a large amount of gas, but did not ignite it. In the similar instance, this same chlorinator reacts instantly with DMSO producing gas but no ignition.

A compound that is said to ignite turpentine is chromyl chloride, CrO2Cl2. This is easy to make, but it is nasty stuff. It is also said to ignite acetone, ethanol, ether, H2S, NH3, sulfur, urea, and explode moist phosphorus.

[Edited on 18-7-2008 by Schockwave]
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[*] posted on 18-7-2008 at 01:49


HNO3 conc + KClO3 in significant amount will burst into flame

H2O2 (50%) + red phosphorus (10 second delay)...evolution of acidic white smokes

KMnO4 + glycerine or glycol (from a few second to a few minutes delay) hanging on the cristal size, the size of the batch and the external temperature..glycol will react faster than glycerine because it is less viscous. In winter can take serval minutes while in summer 1/3 of a minute :)

H2O2 (50%) + Aceton + HCl (35%) at ambiant T without cooling boils and then makes a big cloud of tear gas... for sure explosive with H2SO4 conc as explained above by Shockwave ...

Na, K, Rb, Cs with water...the two last are super explosive.

...

[Edited on 18-7-2008 by PHILOU Zrealone]




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wink.gif posted on 18-7-2008 at 02:06


Quote:
Originally posted by PHILOU Zrealone
HNO3 conc + KClO3 in significant amount will burst into flame

H2O2 (50%) + red phosphorus (10 second delay)...evolution of acidic white smokes

KMnO4 + glycerine or glycol (from a few second to a few minutes delay) hanging on the cristal size, the size of the batch and the external temperature..glycol will react faster than glycerine because it is less viscous. In winter can take serval minutes while in summer 1/3 of a minute :)

H2O2 (50%) + Aceton + HCl (35%) at ambiant T without cooling boils and then makes a big cloud of tear gas... for sure with H2SO4 conc as explained aboveby Shockwave explosive...


Hi Louis. The glycerin reaction is classical. I think KMnO4 might also ignite some glycol ethers. As a control to the 90%, in the same instance with 35% H2O2 and H2SO4 there was no reaction with acetone, not even gas evolution. But that is also at small amounts.
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[*] posted on 18-7-2008 at 06:17


"instance with 35% H2O2 and H2SO4 there was no reaction with acetone"

- forgive me, but doesn't that make a well known dimeric peroxide?




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[*] posted on 18-7-2008 at 11:36


I don't know and doubt if they will survive that strong of an acidity. Wether the trimer or dimer forms is dependent on reaction temperature, with cooler temperatures favoring the trimer. But the point is there was no ignition, gas evolution, etc. as with the almost explosive violence that highly concentrated peroxide reacts with at the drop level.
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[*] posted on 18-7-2008 at 15:26


Acetone peroxide is created using a small amount of acid catalyst. Excess acid can produce mesityl oxide or diacetone alcohol.

As for having no reaction between acetone, H2O2 and H2SO4, that is strictly impossible unless the H2SO4 was highly dilute. H2SO4+35% H2O2 will make something called "Pirahna Soultion" that is not only capable of massacring anything organic, but also oxidizing carbon to carbon dioxide.

That said, it shouldn’t necessarily 'explode,' but there will be a reaction.

Ancillary: KMnO4 has been known to ignite Ethylene Glycol slightly slower than it does glycerol.


[Edited on 7-18-2008 by ShadowWarrior4444]




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[*] posted on 18-7-2008 at 16:09


No mention of calcium hypochlorite? With glycerine, in small quantities, no flame but rapid gas evolution after delay. I suspect 10's of gram quantities would inlfame but I have not tried this because of phosgene generation. I am fairly sure phosgene is generated because the smoke is pungent in a sweetish way totally unlike HCl and Cl2. Hypochlorite and other solid chlorinators seem to inflame with brake fluid which is made up various polyglycols. I wonder about hydochlorite and the alcohols when not confined. Obvously they give off a loud report when in closed containers but you never see a flash.



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[*] posted on 25-7-2008 at 05:59


Quote:
Originally posted by ShadowWarrior4444
Acetone peroxide is created using a small amount of acid catalyst. Excess acid can produce mesityl oxide or diacetone alcohol.

As for having no reaction between acetone, H2O2 and H2SO4, that is strictly impossible unless the H2SO4 was highly dilute. H2SO4+35% H2O2 will make something called "Pirahna Soultion" that is not only capable of massacring anything organic, but also oxidizing carbon to carbon dioxide.

That said, it shouldn’t necessarily 'explode,' but there will be a reaction.


To be clear, in such small amounts these don't react visibly. But in larger amounts, it's a different story.

Quote:
Ancillary: KMnO4 has been known to ignite Ethylene Glycol slightly slower than it does glycerol.


Both glycol and brake fluid (polyalkylene glycol ethers) react a bit quicker than glycerol, brake fluid quicker than glycol. Powerlabs also tested propylene glycol and found this took even longer than glycerin. DMSO reacts instantly with KMnO4, but the only way I’ve gotten an ignition with this, is if the KMnO4 was pulverized to a fine dust. The brake fluid has quite a short delay and out of all of these seems to produce the most powerful burning flame.

Quote:
Originally posted by chloric1
No mention of calcium hypochlorite? With glycerine, in small quantities, no flame but rapid gas evolution after delay. I suspect 10's of gram quantities would inlfame but I have not tried this because of phosgene generation. I am fairly sure phosgene is generated because the smoke is pungent in a sweetish way totally unlike HCl and Cl2. Hypochlorite and other solid chlorinators seem to inflame with brake fluid which is made up various polyglycols. I wonder about hydochlorite and the alcohols when not confined. Obvously they give off a loud report when in closed containers but you never see a flash.


Here is what Brethericks says about Ca(OCl)2: “Contact of the solid hypochlorite with glycerol, diethylene glycol monomethyl ether or phenol causes ignition within a few min, accompanied by irritant smoke, especially with phenol (formation of chlorophenols). Ethanol may cause an explosion, as may methanol, undoubtedly owing to formation of the alkyl hypochlorites. Reaction with polyethylene glycol hydraulic fluid may produce ignition, with a fireball.”

I’ve tried it with brake fluid onto small powdered piles (around the 1 to 2g range) of aged Ca(OCl)2 (65%, rest is inert), trichloro-s-triazintrione (TCCA), sodium dichloro-s-triazinetrione, and the halogenator above comprising halogenated hydantoins. None of them showed a visible reaction after sitting several minutes, besides later some of them gave a little gas evolution or color changes. I also got no visible reaction of few drops glycerin absorbed onto small piles of sodium dichloro-s-triazinetrione, trichloro-s-triazinetrione, and the several years old Ca(OCl)2 (maybe too old, but still has Cl2 smell).

A simple ignition that I would say is worth more and fail-proof than alcohol attempts is with sodium dichloro-s-triazinetrione. Dripping DMSO onto a small powdered pile of this will instantly cause a flame and a sustaining fire to form. This even works with DMSO which has 10% H2O in it. The gases from this reaction are awful and should also not be inhaled.



Chromyl chloride: this is a dark red liquid which strongly fumes, and its fumes will quickly color materials (plastics, stone, etc) yellow and red like its fumes, to even black, and it must not be handled without something like a gas mask, chemical resistant gloves and good ventilation. I did several experiments with this one, at first the reactions were done on a flat surface, then in small dishes.

On the flat plane: 3 drops turpentine had dropwise 3 drops CrO2Cl2 added, eventually after about the third drop a flame quickly flashed out but no fire. Few drops chloride with a few drops acetone gave no visible interaction. 1 drop CrO2Cl2 no visible interaction with 1 drop DMSO. 4 drops dropwise CrO2Cl2 onto 2 drops glycerol gave no visible reaction. 1 drop CrO2Cl2 onto 2 drops brake fluid (glycol ethers) fizzed slightly, no significant gas release. 1 drop CrO2Cl2 added to few drops ether caused sizzling, some gas but no ignition. Few drops chloride dropwise onto a pile of sulfur flowers caused sizzling and gas evolution, but no ignition. A couple drops chloride onto a tissue didn’t sizzle or ignite. By no visible reaction I mean: ignition, sizzling, gas evolution.

In separate small shallow dishes: 2 drops CrO2Cl2 dripped into 5 drops ethanol instantly caused a flame to flash out strongly and ignite the ethanol. 1 drop CrO2Cl2 ignited 5 drops methanol on contact. Several drops ether in the dish then dropwise CrO2Cl2 several drops, this only sizzled and gas release, and again no ignition. 6 drops turpentine caught on fire from 1 drop chloride, but the alcohols seemed more vigorous in ignition. 8 drops acetone from 1 drop CrO2Cl2 added, it gave sizzling reaction and red gases, no ignition; the same is with 8 drops M.E.K. and 3 drops chloride added dropwise, but the reaction seems weaker.

I also tried some reactions with liquid N2O3 (indigo blue liquid), and it is not a very exciting substance (no ignition with ethanol, ether, toluene, or DMSO in the drop amounts on a flat surface). Chromyl chloride was a more interesting oxidizer.

Concerning alkali metal reactions with water. The reaction of sodium seems more or less predictable if it will ignite and burn when put onto water in small pieces. When I was a teen I was trying to form Na2O2 by heating Na metal in air, this amount of Na was about as much as that seen in this video reacting with water. It did form a solid layer and stuck to the glass, but for some reason I threw it into a paint bucket containing water and it caused a loud explosion and a massive volume of gas. Na2O2 itself will react violently with water and powdered metals. I can't verify it again, but I think the Na reacted with the Na2O2 to produce a more violent reaction.


Request to moderators: I think this thread title would be appropriately "Hypergolic reactions", and in my beginning post it should read compounds which "substances that ignite or explode by mixing". Since this thread also largely covers ignition reactions.
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[*] posted on 26-7-2008 at 19:09


Quote:
I think the Na reacted with the Na2O2 to produce a more violent reaction.


Either this, or the sodium which got stuck to the glass got dragged under water causing the sodium to react all at once as instead of dancing on top of it and fizzing around igniting at will like it usually does in those amounts.
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[*] posted on 21-8-2008 at 15:22


Another simple oxidant worth investigating is bromine trifluoride (BrF3) made by just combining F2 with Br2. Much more reactive, toxic and difficult to handle than CrO2Cl2, being a strongly poisonous fuming liquid which is said to react explosively with water, and possibly be able to explode on contact rubber, plastics and organics. It is said to explode on contact with ether or acetone. Violent reaction with many compounds and materials like cork, wax, etc. A milder one but still strong oxidant to experiment with would be IF5, this can be made from I2 and F2 (e.g. US4108966). For an amateur it could be possible to distill I2 and AgF in a copper vessel and collect the IF5 in Cu (forms passive fluoride layer) or PTFE container.
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[*] posted on 22-8-2008 at 07:09


IF7 is preferentially formed by direct reaction of I2 with F2, however. I understand that IF5 tends to disproportionate to IF7 and F2.
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[*] posted on 3-12-2008 at 23:13


I've tried other oxohalogenates also. KBrO3: 0.4 g KBrO3 and 5 drops EtOH (95%), 1 drop conc H2SO4 just sizzles and gives white and red fumes; the same if more H2SO4 is added dropwise. Then: 0.2g KBrO3, 2 drops 90% DMSO, and 1 drop H2SO4 decomposed under fizzing and large gas evolution also with no ignition. 0.3 g KBrO3 mixed with 0.1 g cane sugar, after 1 drop H2SO4 this mixture immediatley ignited and goes nearly as a flash powder with a bright white-blue light, large gas cloud and creating noise as it burns. For comparison, 0.3 g KClO3 and 0.1 g cane sugar mixture ignited from 1 drop H2SO4, and burns vigorously with a purplish flame, it typically burns slower than the -BrO3. The videos of these two reactions are below.

KIO3: 0.3 g KIO3 and 0.1 g cane sugar mixed, 1 drop H2SO4 showed no reaction, 3 drops more and still no reaction. 0.2 g KIO3 and 2 drops 95% EtOH, then 1 drop H2SO4; nothing. After 2 drops acid, the same even after mixing them around and still no reaction. I didn't expect much from the KIO3, it's a flimsy oxidizer.

http://rapidshare.com/files/170080763/KBrO3-sugar.MOV.html
http://rapidshare.com/files/170081423/KClO3-sugar.MOV.html
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[*] posted on 4-12-2008 at 06:37


@Formatik: About the piranha-solution with carbon: Does it also oxidize graphite ? And at what rate ? Is there a possibility, that CO can be generated ?
Does the carbon have to be finely divided, or will it attack larger pieces at a considerable rate ?
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[*] posted on 4-12-2008 at 10:40


Sucrose/NaClO3 (dried) mixtures ignite readily when conc. HCl is droppered on them.
The reaction surprised and mystified me as a child.
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[*] posted on 4-12-2008 at 18:39


Quote:
Originally posted by chief
@Formatik: About the piranha-solution with carbon: Does it also oxidize graphite ? And at what rate ? Is there a possibility, that CO can be generated ?
Does the carbon have to be finely divided, or will it attack larger pieces at a considerable rate ?


I haven't tried but think it should dissolve graphite. My only experience with Piranha and carbon is using it to dissolve carbonaceous residues from glass apparatuses, where I had to heat it to get it to work.

Quote:
Originally posted by hissingnoise
Sucrose/NaClO3 (dried) mixtures ignite readily when conc. HCl is droppered on them.
The reaction surprised and mystified me as a child.


I have tried using conc HCl (>31%) as an initiator and it didn't work. 0.3 g KBrO3 and 0.1 g sugar mix in a volcano-pile and it strongly effervesced (Cl2) from 1 drop conc HCl, more drops caused the same, it didn't ignite. Then I tested this with 0.3 g KClO3 and 0.1 cane sugar mixture in a volcano-pile, this turned green from 1 drop conc HCl, waiting a few seconds, more drops did the same and this also didn't ignite. HNO3 likley could pull off an ignition (if not conc, then fuming).
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