General Chemistry Thread

Freezing, melting, boiling/evaporation, condensation and sublimation and probably the most well know versions of what said.

These are also known as "phase changes".

Can't forget deposition.

edited 1st May '15 12:20:11 AM by rmctagg09

I wonder what the hell is going on in here.

It's aliiiiiive!

I dont know.

Whatever it is, I sure as hell don't want to clean that up.

Random rambling.

I remember making a bet with a friend. I said, I can drink a whole bottle of household chemical...but I never specified what, and won the bet by drinking a bottle of water.

edited 14th May '16 3:11:14 PM by dRoy

Since certain compounds of fluorine and all but a very few compounds of nitrogen are absurdly explosive, would it be plausible if a fictional compound containing both elements was similarly super-explosive?

Actually, nitrogen trifluoride is fairly stable. So .. no?

Tettrafluorohydrazine is explosive when exposed to organic substances and nitrogen pentafluoride may also be, but nothing exceptional.

edited 7th May '17 8:05:50 AM by SeptimusHeap

What's more polarizable: Cyclohexane or Benzene? I'm leaning towards Cyclohexane but I've heard conflicting answers from different sources.

EDIT: Nitrogen triiodide is highly explosive, if you want a replacement.

edited 19th Jan '18 5:06:22 AM by Elfhunter

"Polarizable" in which sense?

In terms of Dipole-Induced dipole interactions, also known as the Debye force.

edited 19th Jan '18 2:15:11 AM by Elfhunter

Cyclohexane is more polarizable I believe, considering that its melting and boiling points are a tiny bit higher.

Well, Melting point has less to do with polarizability and more to do with steric considerations, but yeah higher boiling point would imply higher polarizability.

EDIT: Well, sort of, I have to assume that the energy required to ionize Cyclohexane is also lower for that to be true, since boiling points of non-polar substances depend on London forces.

edited 19th Jan '18 5:25:26 AM by Elfhunter

By any chance does someone know how to calculate heat transfer between an gas pipe that is about 100 C° and either 20C° water and a 20C° mixture of water and ammonia (40 percent of ammonia) and has about 34 in³ surface area of copper piping? And if anyone is curious the said object has 3 layers and Is apart of a cooling tower.

edited 26th Jan '18 5:59:23 PM by Coleman

Isn't that purely a physics question? Or is there a chemical reaction involved that I'm unaware of?

edited 26th Jan '18 6:51:25 PM by MarqFJA

Well I guess it's both physics and chemistry.

When it comes to inventing forms of exotic matter to serve as Applied Phlebotinum, how much leeway do I have in deciding upon said exotic matter's properties before it may break Willing Suspension of Disbelief and/or reaches Science in Genre Only territory?

Example: In a story setting that I'm developing, there's an alien race of humanoid-based centauroids whose bodies' non-humanoid portion is basically a gigantic chimerical arthropod ^note well, more like "pseudo-arthropod"; it has a lot more in common with vertebrate animals, especially mammals, than a first glance impression would imply. For one, they have a closed circulatory system with a dedicated heart., and the planet they hail from is home to other humanoid species with similar arthropod-like morphologies (alongside other, non-arthropod-based ones, of course). To handwave all the issues with the physical possibility of these species' arthropod-like bodies that can't be solved with a "simple redesign" of their biology^note Like giving them a closed circulatory system instead of the open one that is typical to Terran arthropods. — such as the Square-Cube Law possibly getting in the way of their ability to support their own weight — I invented Exotinium-Z396 (placeholder name) as an exotic element that is abundant on their homeworld, but is so exceedingly scarce anywhere else across the universe that it's pretty much Unobtainium Up To Eleven for any other civilization.

But then I ran into another problem: The first alien race I mentioned are supposed to eventually develop into a spacefaring race that proceeds to take their warlike culture to its logical conclusion and essentially start an Forever War against every other spacefaring civilization, humankind included... but how can I have that happen if their biology is dependent on having this element in plentiful supply, when the element is supposed to so rare across the known universe that nobody else can make practical use of it the way this species can?

The one solution that I have hit upon is to take a page from Command & Conquer: Tiberium Wars, and make Exotinium-Z396 capable of self-replication through converting atoms of other elements into more Exotinium-Z396 atoms under specific conditions that are, for one reason or the other, so infrequently occuring in nature that the question of "Why hasn't the aliens' home planet been converted into a solid mass of Exotinium-Z396?" doesn't need to be asked.

Does this seem plausible so far?

edited 6th May '18 4:13:28 PM by MarqFJA

You could also make it so that their homeworld is more or less used up because almost all of it was converted into Exotinium thanks to their abuse of it and said Exotinium is also almost gone. Which offers another justification for warring against other worlds — they want to convert those worlds into more Exotinium.

Just don't make it too much like the Scrin and have them also be addicted to the stuff like a bunch of crack addicts.

edited 6th May '18 6:31:07 PM by M84

No matter how rare it is, there are going to be other deposits somewhere. Not to hard to arrange small deposits distributed evenly across the galaxy—bringing them into conflict with everyone else.

Necro and a random confession.

For a very long time, I actually thought water was an organic compound. My logic went as followed:

All living organisms need water.

All living organisms are, well, made of organic materials.

Ergo, water must be organic.

But no, apparently that's not how chemistry (nor biology) works.

Necroing because the first question posed in my last post remains unanswered: When it comes to inventing forms of exotic matter to serve as Applied Phlebotinum, how much leeway do I have in deciding upon said exotic matter's properties before it may break Willing Suspension of Disbelief and/or reaches Science in Genre Only territory?

"Exotic matter" is a very broad concept. You'd need to mention what kind of matter you are talking about and then follow its properties.

The kind I'm thinking about is a stable form of exotic atoms composed of fictional subatomic particles.

Edited by MarqFJA on Feb 2nd 2020 at 5:32:26 PM

You'll need to specify some of the traits of the particles. Mainly their mass, electric and colour charge and their stability.

... You make it sound as if these properties impose absolutely hard limits on what I can do.