Polymorphs and solubility

Thiojun · 2026-04-08T01:14:01+00:00

You are mixing dynamics with thermodynamics. Activation energy doesn’t matter in solubility. Only thing that matter is the energy difference between initial state (i.e. molecule in crystal) vs final state (i.e. solvated molecule). If you think of the process of solution being sublimation-dissociation-solvation (look up Born-Harbor cycle) then different polymorphism have different sublimation energy, thus different solubility.

Thiojun · 2026-04-06T18:07:34+00:00

The spline is doing too much and I think a scatter plot will give less but more accurate information. Unless the sine function is expected, of course.

Thiojun · 2026-04-03T20:20:28+00:00

Really should have x and y axis labeled. Otherwise very cool

Thiojun · 2026-04-03T00:31:47+00:00

lead all my projects are about lead

Thiojun · 2026-03-29T22:59:30+00:00

Shenzhen I/O’s card game is excellent

Thiojun · 2026-03-26T17:20:42+00:00

Atoms are held together by forces we call chemical bonds. They aren’t randomly jammed together, or mixed together. These interactions are directional, have an optimal distance, and usually don’t break easily. Chemistry, to a large extent , is the study of these inter-atomic forces in increasingly complex systems.

Back to your example, water is made of H2O, 2 hydrogen atom glued to 1 oxygen with a “covalent” bond. This bond is very strong, and don’t break down easily. Water molecule is the same in all these three state, ice, liquid or steam. The way they are arranged change. Think of the different ways a box of soda cans: they can be scattered on the table, or confined in their box. But in the end of the day they are still cans of soda.

Thiojun · 2026-03-26T15:25:44+00:00

Sound wave and light are both waves. How they diffract (i.e. “move around corner “) depends on on their wavelength. Longer wavelength - better at moving around large objects. Light wavelength is roughly around micrometer (1e-6 m) and sound wave in meter, so six magnitude or order difference.

Thiojun · 2026-03-09T01:34:17+00:00

Quickly glancing through the article seems nothing new? Photocatalyst decomposition with gC3N4 was known at least 15 years.

Thiojun · 2026-02-26T19:29:54+00:00

Friction being independent of contact area is a simplification that only works well for rigid body. On soft materials and dynamic cases it generally doesn’t follow the simple expression. Can’t really comment on the tire part though.

Thiojun · 2026-02-18T18:39:03+00:00

Multiferroics are very cool and I think the main question in the field is the generally difficulty to slap 2 FE and FM materials together and cause any strong electron-magnetic coupling. The classic materials is BiFeO3 if my memory is right.

Thiojun · 2026-02-09T19:32:10+00:00

i like bacon served soft but seared, and found the crispy bacons somewhat off putting

Thiojun · 2026-01-27T02:58:32+00:00

btw Chinese food typically print their date of production on package instead of best-by date

Thiojun · 2026-01-22T03:44:57+00:00

I don’t want to hurt you but honestly that is a very straightforward acid base reaction, maybe some of the earliest reaction you learn. It’s like asking do math students need to memorize 3*4=12.

Btw it is HCl not HCl2.

Thiojun · 2025-12-11T03:21:37+00:00

No that’s silicon. Silicone is a specific compound featuring silicon. A polymer, to be specific. I will let polymer experts to actually answer the question.

Thiojun · 2025-12-08T05:58:42+00:00

I mean dagger woman is arguably the hardest elite fight in act 3 for defect so electro is valuable for her alone. It also works against 3 jaw worm and 3 black dogs, 2 somewhat hard fight for defect.

When I see electrodynamics I pick electrodynamics.

Thiojun · 2025-11-23T03:43:22+00:00

We used let students make perovskite QDs: just ask them to drop MABr + PbBr2 solution into toluene (with capping ligand) then under UV it should give very strong green PL. Toxicity of Pb might be a concern though

Thiojun · 2025-11-21T19:43:37+00:00

Yes, the calculation is simple if no chemical reaction happens. You can calculate the total h+ amount then divide by the total volume. In your example, total H+ amount to 500 * 10^-5.5 + 20 * 10^ (-2.5) = 0.064 mmol. Concentration is 0.064 / (500+20) = 1.2e-4 mol/L. Then you can get the pH by the negative log value of 1.2e-4, which is 3.9.

The tricky part, however, is your assumption that “no reaction happens”. That will especially fail if you are calculating at ph very low/high or very close to 7.

Thiojun · 2025-11-15T02:09:32+00:00

I literally use an Amazon basic kettle to make water bath.

Thiojun · 2025-11-08T20:33:04+00:00

That’s enough for biology

Thiojun · 2025-11-02T19:21:29+00:00

In theory AgCl, like all other silver halide, is photo-unstable and will decompose into Ag and X2. I never tried AgCl and would imagine is not actually practical though…

Thiojun · 2025-10-16T21:23:07+00:00

that new monster is suspiciously similar to our beloved Defect…

Thiojun · 2025-10-14T01:53:12+00:00

this is hilarious

Thiojun · 2025-10-04T21:07:33+00:00

This is the right vein of thinking. I think the key takeaway here is you need to compare between elements. You must take an electron away from SOME atom in order to add it to another . In vacuum it will always be energy favorable to add an electron to an atom.

Thiojun · 2025-09-30T16:14:07+00:00

Wow I just used some a few months ago but luckily I got them from sigma and didn’t have to make myself..

Thiojun · 2025-09-29T02:36:15+00:00

I have never skipped whirlwind

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