11–20 of 78 posts
I've never thought anything related to chemistry was simple, so if it really is more complex then I'm glad I'm in IT.
I was an EE/CS major and getting A's in the two chemistry courses I took in college is one of my proudest achievements because I had to work so hard for them. Nothing about chemistry was intuitive or simple for me.
I remember a bit of this in undergrad gen chem. If pH stands for -log([H+]), how can pure water (H2O) have a pH of 7? In theory, there shouldn't be any hydrogen ions in pure water. Turns out there are two simplifications being made: i. H+ in aqueous solution is synonymous with hydronium ion (H3O+). ii. Water is in an equilibrium autoionization reaction with itself and the hydronium and hydroxide ions: 2H2O H3O+ + OH-…
Perhaps we've ended up full circle on this again as the current leading theory is H₂O actually forms the cation H⁺·(H₂O)₂·(H₂O)₄, where the H⁺ forms a hydrogen bond to two H₂Os which form two more hydrogen bonds to two H₂Os each: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946644/
I remember a bit of this in undergrad gen chem. If pH stands for -log([H+]), how can pure water (H2O) have a pH of 7? In theory, there shouldn't be any hydrogen ions in pure water. Turns out there are two simplifications being made: i. H+ in aqueous solution is synonymous with hydronium ion (H3O+). ii. Water is in an equilibrium autoionization reaction with itself and the hydronium and hydroxide ions: 2H2O H3O+ + OH-…
I remember a bit of this in undergrad gen chem. If pH stands for -log([H+]), how can pure water (H2O) have a pH of 7? In theory, there shouldn't be any hydrogen ions in pure water. Turns out there are two simplifications being made: i. H+ in aqueous solution is synonymous with hydronium ion (H3O+). ii. Water is in an equilibrium autoionization reaction with itself and the hydronium and hydroxide ions: 2H2O H3O+ + OH-…
Perhaps we've ended up full circle on this again as the current leading theory is H₂O actually forms the cation H⁺·(H₂O)₂·(H₂O)₄, where the H⁺ forms a hydrogen bond to two H₂Os which form two more hydrogen bonds to two H₂Os each: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2946644/
Earlier quoted context omitted.
I think my mind was first blown when our physics teacher asked us if H2O conducts electricity. And naturally we all said yeah[1]. We were naturally wrong, but pure water is amazing in its own right. edit: decided to add an edit just in case someone tries to test this claim [1] https://www.usgs.gov/special-topics/water-science-school/sci...
Water ice is a semiconductor and can be doped, like silicon, to make transistors. https://m.youtube.com/watch?v=o61wtb7dSRA
I remember a bit of this in undergrad gen chem. If pH stands for -log([H+]), how can pure water (H2O) have a pH of 7? In theory, there shouldn't be any hydrogen ions in pure water. Turns out there are two simplifications being made: i. H+ in aqueous solution is synonymous with hydronium ion (H3O+). ii. Water is in an equilibrium autoionization reaction with itself and the hydronium and hydroxide ions: 2H2O H3O+ + OH-…
Free text of the research paper: https://chemrxiv.org/engage/chemrxiv/article-details/6353634...
[1] Note that the H+ is never alone. It's too difficult to remove that electron from the Hydrogen, so H+ is a shorthand for something more complicated.
Earlier quoted context omitted.
Water ice is a semiconductor and can be doped, like silicon, to make transistors. https://m.youtube.com/watch?v=o61wtb7dSRA
This video seems to confuse semiconductors with "materials with a negative thermal coefficient of resistivity". Saying "this gets more conductive as you heat it up" does not a semiconductor make, as far as I understand.
One thing I always wonder is what exactly does HCl dissolve in the stomach, and how does it not destroy the nutritional value of the food?
Acids destroying whatever they touch is mostly a "kiddie" version of reality. 99.9% of acids found outside of chemistry labs and industrial settings are no more dangerous or destructive (as acids) than soda pop, lime juice, or human vomit (all of which are acids).
The reason is that some far stronger and/or more dangerous acids occasionally show up in household settings. Example: "battery acid", splashed on the skin, can cause horrific & life-long damage in seconds. Teaching kids to stay far away from anything labeled "Acid" is kinda like teaching 'em not to play with fire.