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Is there a chemical compound which does not have a liquid state but a solid and a gaseous state? Meaning no matter the temperature or pressure it will never be in its liquid form. According to my rather basic knowledge of chemistry this means that it has a critical temperature lower than the melting point.

I have seen this question already, but it only talks about elements and not compounds.

SirHawrk
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    Lots of them. They decompose on heating before they would melt, like hydrate salts, most hydroxides and carbonates, etc. – Oscar Lanzi Aug 26 '22 at 11:27
  • @OscarLanzi I updated the question. I meant things that have solid and gaseous forms but no liquid forms – SirHawrk Aug 26 '22 at 11:29
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    Most organic compounds decompose before melting. So is there many unstable inorganic compounds, that decompose if the frost is not deep enough, or before reaching melting point. – Poutnik Aug 26 '22 at 12:31
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    https://chemistry.stackexchange.com/questions/31050/can-you-melt-wood https://chemistry.stackexchange.com/questions/62539/why-don-t-all-objects-melt-and-liquefy-when-heated-sufficiently – Mithoron Aug 26 '22 at 13:35
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    https://chemistry.stackexchange.com/questions/94003/what-are-some-examples-of-pure-substances-with-no-liquid-state – Mithoron Aug 26 '22 at 13:36
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    Neither of these actually answer the question if any of these compounds have a solid & and a gaseous state but no liquid state, as they decompose before they would be either gaseous or liquid. So no these do not actually answer my question. @Mithoron – SirHawrk Aug 26 '22 at 13:38
  • That still has nothing to do with any critical points, only chemical reaction. – Mithoron Aug 26 '22 at 13:53
  • Then my rather basic chemical knowledge was just plain wrong :D – SirHawrk Aug 26 '22 at 13:54
  • It could be summarized that compounds with sufficient thermal and chemical stability do have their liquid phase, if there is high enough pressure available. A special case is liquid carbon, where 100-1000 atm at 4500-5000 K is needed. – Poutnik Aug 26 '22 at 14:00
  • .....uhh, naphthalene – Nilay Ghosh Aug 27 '22 at 06:22
  • @NilayGhosh Only if sealed piece of naphtalene wouldn't melt because of decomposition. – Mithoron Aug 27 '22 at 13:55

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