6 ms·

Yeah it kind of defeats the point when your definition of 'doesn't burn' covers every single substance.

by contravariant 5y ago

dragontamer 5y ago
Except Li-ion batteries, which burn with their own oxidizer.
- hobs 5y ago
  Well there's plenty of monoprops that supply their own oxidizer, and oh boy are they absolutely dangerous as hell. https://en.wikipedia.org/wiki/Monopropellant https://en.wikipedia.org/wiki/Monopropellant
- yellow_lead 5y ago
  And rocket fuel? Technically
  - dragontamer 5y ago
    Rocket fuel is more of a "pre-mixed with oxidizier" sorta thing. Although I am enjoying the side discussion about monopropellants.
  - gpm 5y ago
    Most modern rockets are liquid and mix the fuel and oxidizer only at the point of combustion, burning H2/O2, Kerosene/O2 or more recently CH4/O2. Mono-propellant, and solid (not hybrid) rocket fuel fits the description though
    - crazydoggers 5y ago
      > Mono-propellant, and solid (not hybrid) rocket fuel fits the description though Decomposition doesn’t count as “burning” which means combustion. Fusion and fission release energy as well, but I don’t think anyone calls fusion “burning” hydrogen.
      - gpm 5y ago
        Generally I don't think this type of language debate is useful, we aren't debating what is happening, just what to call it, and that's pretty boring. If you want to call it not burning, ok, be my guest. Hopefully my answer is still an interesting point about the kinds of violent chemical reactions that exist and could make a substance dangerous to work with in an environment without (outside, in the case of solid rocket fuel) oxidizing agents. I'll make an exception and reply about the language in this case because I there's a broader point I want to make: English isn't a language defined based of "X happens if chemical reactions Y happens behind the scenes", because we didn't even know about chemical reaction Y when English was invented. Moreover if you tried to define it as oxidation you'd fail, rust isn't burning, meanwhile (non-oxidizing) chemical burns, sunburns, etc all exist because they were just analogous enough to the concept of fire. If people knew about some chemical that decomposes into plasma in the 1600s, they definitely called it burning even if there was no oxidation. Meanwhile people definitely refer to fusion as "burning", e.g. see this stackexchange question with lots of links to wikipedia and the like which refer to different kinds of fusion as burning [1] or ctrl-f burning in this wikipedia article [2] (which is linked from [1]). [1] https://astronomy.stackexchange.com/questions/43907/hydrogen-burning-vs-hydrogen-fusing https://astronomy.stackexchange.com/questions/43907/hydrogen... [2] https://en.wikipedia.org/wiki/Stellar_nucleosynthesis https://en.wikipedia.org/wiki/Stellar_nucleosynthesis
        crazydoggers 5y ago
        I don’t really take this as a language debate though. It clearly is about the fact that people don’t understand what an oxidizer is at a chemical level. Someone who says the following isn’t just using language inaccurately, it actually shows a fundamental misunderstanding of combustion: > pure hydrogen doesn’t burn. It needs an oxidizer—like the oxygen in air. That statement, no matter how you take it, leaves an assumption that other gases might burn like hydrogen without oxygen, which is again a fundamental misunderstanding of chemistry. In addition calling something “self oxidizing” doesn’t make sense. There are always mixtures of fuel and oxidizers… whether those are gas and fuel, solid and fuel, mixed in gunpowder form, mixed as gasoline and air in a carburetor, etc. So if I supply you a balloon with the proper stoichiometric ratio of gasoline and air, is that “self-oxidizing”? If so then everything is self oxidizing. And while I would agree that people do refer to fusion as “burning” I actually think this is a again a prime example of people not understanding the underlying physics. Most people don’t understand how fusion works, so calling it “burning” is a lazy way to conceptualize what the sun is doing. Scientists will sometimes use “burning hydrogen” when talking about nucleosynthesis, but they assume the audience of other scientists understand the difference between combustion and fusion. When articles like the original post are talking to the layperson in this manner however, it does nothing but lead to more scientific illiteracy. A perfect example is one of the above comments: > There are rumours that because of this fact, that the Hindenburg disaster was not from natural causes. If we don’t communicate science effectively then we end up with conspiracies and pseudoscience. Words are tools. They should be used wisely.
gpm 5y ago
Self oxidizing mixtures exist. Gun powder is probably the classic example. Monopropellants, that aren't mixtures, exist and "burn" too, high concentration H2O2 for instance.
- toomanybeersies 5y ago
  T-Stoff/High-Test Peroxide doesn't actually burn, but rather decomposes into water and oxygen.
- rbanffy 5y ago
  They can still burn in the presence of an oxidiser. They don't need it, but that won't stop them from burning, or blowing up, or doing whatever they want to do, as monopropellants are really (no pun intended) impulsive.
- crazydoggers 5y ago
  Gunpowder still requires an oxidizer, it just happens to be mixed in. The potassium nitrate is the oxidizer, KN03, whereas the sulphur and charcoal are the fuels that burn. Pretty much any combustion requires a molecule with oxygen to accept the electrons: exceptions exist with halogens like chlorine… but these are still called “oxidizers” So saying hydrogen doesn’t burn without an oxidizer still makes little sense. Hydrogen will combust with either oxygen or chlorine for example, both oxidizers. Without those then nothing happens because nothing can combust without an oxidizer… You may just not realize the oxidizer is mixed with the fuel.
  - jandrewrogers 5y ago
    Technically speaking, sulfur is an oxidizer in gunpowder, not fuel. Sulfur is even in the same elemental group as oxygen. Sulfur is commonly used as an oxidizer for metal fuels. In the case of gunpowder, that would be the potassium in potassium nitrate.
    - crazydoggers 5y ago
      That’s not correct. (Sulfur can be an oxidizer in some reactions as you mention, but not in gunpowder where it acts as the fuel) https://www.wikipedia.org/wiki/Gunpowder#Components https://www.wikipedia.org/wiki/Gunpowder#Components Potassium nitrate is the most important ingredient in terms of both bulk and function because the combustion process releases oxygen from the potassium nitrate, promoting the rapid burning of the other ingredients Sulfur's main role in gunpowder is to decrease the ignition temperature. A sample reaction for sulfur-free gunpowder would be: 6 KNO3 + C7H4O → 3 K2CO3 + 4 CO2 + 2 H2O + 3 N2

Yeah it kind of defeats the point when your definition of 'doesn't burn' covers every single substance.

dragontamer 5y ago

Except Li-ion batteries, which burn with their own oxidizer.

hobs 5y ago
Well there's plenty of monoprops that supply their own oxidizer, and oh boy are they absolutely dangerous as hell. https://en.wikipedia.org/wiki/Monopropellant https://en.wikipedia.org/wiki/Monopropellant
yellow_lead 5y ago
And rocket fuel? Technically
- dragontamer 5y ago
  Rocket fuel is more of a "pre-mixed with oxidizier" sorta thing. Although I am enjoying the side discussion about monopropellants.
- gpm 5y ago
  Most modern rockets are liquid and mix the fuel and oxidizer only at the point of combustion, burning H2/O2, Kerosene/O2 or more recently CH4/O2. Mono-propellant, and solid (not hybrid) rocket fuel fits the description though
  - crazydoggers 5y ago
    > Mono-propellant, and solid (not hybrid) rocket fuel fits the description though Decomposition doesn’t count as “burning” which means combustion. Fusion and fission release energy as well, but I don’t think anyone calls fusion “burning” hydrogen.
    - gpm 5y ago
      Generally I don't think this type of language debate is useful, we aren't debating what is happening, just what to call it, and that's pretty boring. If you want to call it not burning, ok, be my guest. Hopefully my answer is still an interesting point about the kinds of violent chemical reactions that exist and could make a substance dangerous to work with in an environment without (outside, in the case of solid rocket fuel) oxidizing agents. I'll make an exception and reply about the language in this case because I there's a broader point I want to make: English isn't a language defined based of "X happens if chemical reactions Y happens behind the scenes", because we didn't even know about chemical reaction Y when English was invented. Moreover if you tried to define it as oxidation you'd fail, rust isn't burning, meanwhile (non-oxidizing) chemical burns, sunburns, etc all exist because they were just analogous enough to the concept of fire. If people knew about some chemical that decomposes into plasma in the 1600s, they definitely called it burning even if there was no oxidation. Meanwhile people definitely refer to fusion as "burning", e.g. see this stackexchange question with lots of links to wikipedia and the like which refer to different kinds of fusion as burning [1] or ctrl-f burning in this wikipedia article [2] (which is linked from [1]). [1] https://astronomy.stackexchange.com/questions/43907/hydrogen-burning-vs-hydrogen-fusing https://astronomy.stackexchange.com/questions/43907/hydrogen... [2] https://en.wikipedia.org/wiki/Stellar_nucleosynthesis https://en.wikipedia.org/wiki/Stellar_nucleosynthesis
      - crazydoggers 5y ago
        I don’t really take this as a language debate though. It clearly is about the fact that people don’t understand what an oxidizer is at a chemical level. Someone who says the following isn’t just using language inaccurately, it actually shows a fundamental misunderstanding of combustion: > pure hydrogen doesn’t burn. It needs an oxidizer—like the oxygen in air. That statement, no matter how you take it, leaves an assumption that other gases might burn like hydrogen without oxygen, which is again a fundamental misunderstanding of chemistry. In addition calling something “self oxidizing” doesn’t make sense. There are always mixtures of fuel and oxidizers… whether those are gas and fuel, solid and fuel, mixed in gunpowder form, mixed as gasoline and air in a carburetor, etc. So if I supply you a balloon with the proper stoichiometric ratio of gasoline and air, is that “self-oxidizing”? If so then everything is self oxidizing. And while I would agree that people do refer to fusion as “burning” I actually think this is a again a prime example of people not understanding the underlying physics. Most people don’t understand how fusion works, so calling it “burning” is a lazy way to conceptualize what the sun is doing. Scientists will sometimes use “burning hydrogen” when talking about nucleosynthesis, but they assume the audience of other scientists understand the difference between combustion and fusion. When articles like the original post are talking to the layperson in this manner however, it does nothing but lead to more scientific illiteracy. A perfect example is one of the above comments: > There are rumours that because of this fact, that the Hindenburg disaster was not from natural causes. If we don’t communicate science effectively then we end up with conspiracies and pseudoscience. Words are tools. They should be used wisely.

gpm 5y ago

Self oxidizing mixtures exist. Gun powder is probably the classic example. Monopropellants, that aren't mixtures, exist and "burn" too, high concentration H2O2 for instance.

toomanybeersies 5y ago
T-Stoff/High-Test Peroxide doesn't actually burn, but rather decomposes into water and oxygen.
rbanffy 5y ago
They can still burn in the presence of an oxidiser. They don't need it, but that won't stop them from burning, or blowing up, or doing whatever they want to do, as monopropellants are really (no pun intended) impulsive.
crazydoggers 5y ago
Gunpowder still requires an oxidizer, it just happens to be mixed in. The potassium nitrate is the oxidizer, KN03, whereas the sulphur and charcoal are the fuels that burn. Pretty much any combustion requires a molecule with oxygen to accept the electrons: exceptions exist with halogens like chlorine… but these are still called “oxidizers” So saying hydrogen doesn’t burn without an oxidizer still makes little sense. Hydrogen will combust with either oxygen or chlorine for example, both oxidizers. Without those then nothing happens because nothing can combust without an oxidizer… You may just not realize the oxidizer is mixed with the fuel.
- jandrewrogers 5y ago
  Technically speaking, sulfur is an oxidizer in gunpowder, not fuel. Sulfur is even in the same elemental group as oxygen. Sulfur is commonly used as an oxidizer for metal fuels. In the case of gunpowder, that would be the potassium in potassium nitrate.
  - crazydoggers 5y ago
    That’s not correct. (Sulfur can be an oxidizer in some reactions as you mention, but not in gunpowder where it acts as the fuel) https://www.wikipedia.org/wiki/Gunpowder#Components https://www.wikipedia.org/wiki/Gunpowder#Components Potassium nitrate is the most important ingredient in terms of both bulk and function because the combustion process releases oxygen from the potassium nitrate, promoting the rapid burning of the other ingredients Sulfur's main role in gunpowder is to decrease the ignition temperature. A sample reaction for sulfur-free gunpowder would be: 6 KNO3 + C7H4O → 3 K2CO3 + 4 CO2 + 2 H2O + 3 N2