https://www.explainxkcd.com/wiki/api.php?action=feedcontributions&feedformat=atom&user=172.70.134.39explain xkcd - User contributions [en]2026-04-14T08:03:11ZUser contributionsMediaWiki 1.30.0https://www.explainxkcd.com/wiki/index.php?title=Talk:2943:_Unsolved_Chemistry_Problems&diff=344030Talk:2943: Unsolved Chemistry Problems2024-06-08T04:55:53Z<p>172.70.134.39: </p>
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P stands for poncentration, SMH my head đ --[[Special:Contributions/172.70.162.211|172.70.162.211]] 21:22, 7 June 2024 (UTC)<br />
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Is 'depolymerization' in this context referring to means of chemically recycling plastics? As I understand it, we basically just do recycling of thermoplastics at the moment by physically melting them, whereas being able to split a plastic apart into its component monomers would in principle enable a completely closed loop lifecycle for plastics, easing the strain on dwindling oil reserves and landfills and whatnot. Since these are supposed to be important unsolved problems, I feel like it probably is a reference to this, but I'm not a chemist and there may be something else which makes more sense. [[Special:Contributions/162.158.33.134|162.158.33.134]] 22:37, 7 June 2024 (UTC)<br />
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i've always been taught that the p stood for "parts". [[user talk:lettherebedarklight|youtu.be/miLcaqq2Zpk]] 04:01, 8 June 2024 (UTC)<br />
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:In chemistry, I was taught that it was "potential". I didn't even know this was in dispute. [[User:L-Space Traveler|L-Space Traveler]] ([[User talk:L-Space Traveler|talk]]) 04:54, 8 June 2024 (UTC)<br />
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P does not stand for anything. Originally, it was contrasted with q. Sørensen was performing electrochemical experiments and contrasted the reference electrode q with the hydrogen electrode p. Using p and q like this is common, like using x and y, u and v, or m and n. It's not an abbreviation, just a variable name. He recommended normalizing the concentration of hydrogen ions (i.e. dividing it by 1 mol/l) and calling the result Câ or C_q (depending on the electrode). Then each of these tends to be a small number, which we could write as 10^(-p) or 10^(-q). The number pâş_H then represented the negative log of the normalized concentration of hydrogen cations at the hydrogen electrode. You can read about it in "The origin and the meaning of the little p in pH" by Jens G. Nørby, published in Cell. The associations with words like "power" and "potential" are now widely considered urban legends. [[Special:Contributions/172.70.134.39|172.70.134.39]] 04:55, 8 June 2024 (UTC)</div>172.70.134.39