Dare someone smarter than me explain what the ever loving fuck is going on there?
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, see titanium-nickel phase diagram. Normal case would be eutectic, see aluminum-silicon phase diagram
I see. So these are actually many sulfuric compounds in a trenchcoat chart.
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.
Here’s what a normal curve looks like:
https://i2.wp.com/www.storksplows.com/docs/wp-content/uploads/2017/04/Brine-Pro-salinity-chart.png
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.
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.
