I would like to think of the following equation:
$$\ce{aA(g) + bB(g) -> cC(g)}$$
where $a + b < c$ and $\ce{A},$ $\ce{B}$ and $\ce{C}$ are different gases.
Is there such chemical reaction?
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I think extractions and ire synthesized isobutane from 2 separate gases but he couldn’t correctly synthesize it. You might want to check his channel out on YouTube if your interested. He might of made it correctly because he made multiple videos on it and I didn’t see all of the videos. – 15year old chemist Feb 06 '20 at 02:21
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There are plenty of reactions like this, especially if you go beyond STP, so it would be nice if you also specify the conditions. – andselisk Feb 06 '20 at 05:08
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Burning of nearly any hydrocarbon would do, provided that it returns water in vapor form (which of course it does). – Ivan Neretin Feb 06 '20 at 05:12
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1@IvanNeretin Burning hydrocarbons won't satisfy one of his conditions, which is that the reaction produces a single product. – theorist Feb 06 '20 at 05:19
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@theorist Oops, I missed that one. Well, then all of a sudden there are not that many reactions, and those which are still there look highly unnatural and contrived, like O3+C3O2. – Ivan Neretin Feb 06 '20 at 06:12
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@IvanNeretin Does Ozone react with Carbon Suboxide? If so, thank you very very much for providing your answer! I've been pondering on a seemingly flawed highschool chemistry problem and was thinking of a counterexample to show that it is indeed flawed. Anyway, thanks for the answer! – HOP3Z7c0wcxREDVgAf9WTYDv1c85lY Feb 06 '20 at 07:19
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Well, ozone oxidizes pretty much everything, and C3O2 reacts with pretty much everything, so what are their options? – Ivan Neretin Feb 06 '20 at 07:35
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What about the photochemical reaction $\ce{2O_3 \to 3O_2}$ if you let A and B be the same. – porphyrin Feb 06 '20 at 09:34
2 Answers
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Decomposition of ozone:
$\ce{O3 + O3 -> 3 O2}$
Technically, not 3 different gases, but the introduction of isotopes may be judged as in compliant (and yes, contrived).
AJKOER
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This is a fun question. The essence of what makes it challenging is that you're doing a synthesis -- combining two different species into one -- yet ending up with more particles, not (as is typical) less. This limits the number of possible reactions significantly. Here, however, is one that meets the conditions:
Octasulfur ($\ce {S_8}$) boils at 444.6 $^\circ \text{C}$ at standard pressure. So, above that temperature, one could have:
$$\ce{ S_{8(g)} + 4O_{2(g)}-> 8SO_{(g)}},$$
where $1+4 < 8$.
Of course, if octasulfur were combusted with oxygen, it's likely that many other species of sulfur oxides (i.e., compounds of the form $\ce {S_xO_y}$) would be produced as well.
theorist
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2@Theorist : In the vapor phase, sulfur is not made of S8 molecules, but S2. – Maurice Feb 06 '20 at 15:02
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1@Maurice Do you have a reference to support that? According to https://aip.scitation.org/doi/abs/10.1063/1.1734241 [J. Berkowitz, Equilibrium Composition of Sulfur Vapor, J. Chem. Phys. 39, 275 (1963)]: "Sulfur vapor, as well as...have been studied mass‐spectrometrically. The results indicate the presence of all possible S$_n$ molecules between S$_2$ and S$_8$ in measurable concentration between room temperature and the boiling point of sulfur." Given this, one should also find S$_8$ just above the bp. And, of course, the proposed rxn could also take place below the bp. – theorist Feb 07 '20 at 01:57
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1@Maurice This is not true, see https://doi.org/10.1007/b12405. Reading the abstract should be enough to find out that S₈ is one of the dominating forms in gaseous phase at the temperatures up to 1000 °C. Later, in the chapter it is mentioned that "the ratio of the partial pressures calculated by Detry et al. for saturated sulfur vapor at a temperature of 300 °C is as follows: S₈:S₇:S₆:S₅:S₄:S₃:S₂ = 1:0.35:0.44:0.026:0.001:0.001:0.007." Also, see this table for 500 °C. The theorist's answer looks perfectly fine to me. – andselisk Feb 07 '20 at 03:54
