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Your pH example actually proves the opposite. pH 7 is not neutral because it happens to sit halfway between 0 and 14. pH is not inherently limited to that rang
by Sha1rholder 29d ago
Your pH example actually proves the opposite. pH 7 is not neutral because it happens to sit halfway between 0 and 14.
pH is not inherently limited to that range at all. Sufficiently concentrated solutions can have pH values below 0 or above 14. A solution is called neutral when the activities of hydrogen ions and hydroxide ions are equal, which happens to correspond to about pH 7 at 25°C. Change the temperature and neutral pH changes too. So if you arbitrarily changed the scale to 10–30, that wouldn’t magically make 20 “neutral.” Neutrality comes from the definition and the underlying conditions, not from being the midpoint between two numbers.
- HappMacDonald 27d agoI know it's off topic: but I am curious and this sounds both challenging to search for and likely to not get a straight answer from an LLM. Do you happen to know if this means that water may tip from neutral to slightly alkaline or acidic at different temperatures or pressures? I have always found it .. peculiar that water just so happens to (as you aptly put it) "have all the activities of hydrogen ions and hydroxide ions equal" :)
- Sha1rholder 27d agoThis isn't a difficult question. I'm sure LLM knows these things better than I do. Water is H-O-H; H+ and OH- both come from water. If there are no impurities, then for every extra H+ there is an extra OH-, so it's not that they are "happen to be equal". They're born equal. Changing the temperature does change the concentrations of these ions so pH does change by definition. But the water remains neutral, since the ratio of H⁺ to OH⁻ is still 1:1