My uneducated understanding is that the chart shows at which temperatures sulfuric acid freezes depending on the concentration. Also in my very basic understanding of physics and chemistry I would have thought that it’s linear or exponential or something predictable and not that jumpy.
Comment on freezing point curves
arandomthought@sh.itjust.works 3 months ago
Dare someone smarter than me explain what the ever loving fuck is going on there?
Ravi@feddit.org 3 months ago
skillissuer@discuss.tchncs.de 3 months ago
In normal cases you’d see two curves going away from pure compounds downwards to a common minimum, which is eutectic point
marcos@lemmy.world 3 months ago
Here’s what a normal curve looks like:
phdepressed@sh.itjust.works 3 months ago
Sulfuric acid and water has various H2SO4 and H2O ratios. So like 1 H2SO4 and 6, 3, 2, or 1 H2O it also has just the H2SO4 and H2S2O7. These are present as local points within solutions and with different prominence depending on the amount of water added. These 8 different ratios each have different freezing points.
TheSlad@sh.itjust.works 3 months ago
If I had to guess, I would assume that there are different molecular lattices that sulfuric acid and water can form at different concentrations and that these different lattices have different freezing points. I will now go look it up.
skillissuer@discuss.tchncs.de 3 months ago
What you’re describing are different crystalline phases of pure compounds, but this does not give you new minima, you need some new compound to form for that
Gladaed@feddit.org 3 months ago
Physics.
skillissuer@discuss.tchncs.de 3 months ago
This is what happens when some kind of new compound is formed between these two, here it’ll be series of sulfuric acid-water complexes. Same thing happens with metals when intermetallic compounds form
skillissuer@discuss.tchncs.de 3 months ago
Here is a more complete chart …stackexchange.com/…/details-of-what-actually-hap…
jol@discuss.tchncs.de 3 months ago
I see. So these are actually many sulfuric compounds in a trenchcoat chart.
skillissuer@discuss.tchncs.de 3 months ago
Some of which are probably only a bit stable and so only exist in a mixture
grue@lemmy.world 3 months ago
Never mind between 80 and 90%, WTF is happening at 42.5%‽
skillissuer@discuss.tchncs.de 3 months ago
There’s a metastable phase somewhere out there and change of the most stable solid phase between 4-hydrate and 6.5-hydrate