I don't know if this thread fits here, but I want to post a lot of things I've been thinking about just generally in Physics/Chemistry/"hard sciences" and have been confused by.
1 - ENTROPY
I'm trying to understand entropy. When I left uni, I left with the thought, "IT'S A MEASUREMENT OF DISORDER"/"Proportional to the log of the number of admissable states of a system." But now I've done back to this to actually _think_ about what it means, and I realize I do not understand it.
Let me start off with a really basic question: what's up with the units? How is "Joules per Kelvin" a "measure of disorder?" With those units, I'd expect entropy to be related to "How good an insulator" a material is than anything to do with "disorder."
2 - CHLORINATION & SALTWATER
O.K. so this is difficult to explain in general what the hell is going on with my brain here, but whenever I try to understand something about chlorination, it causes me grief and confusion about why that DOESN'T happen with saltwater. I'll give a few examples:
- Chlorine dissolved in distilled water will become ionic in water, but because it's volatile and reforms into a gas, it eventually comes out of the solution, right? (*) Well then, how come that doesn't happen with saltwater? The chlorine ions would eventually vaporize out of solution leaving the saltwater at least slightly alkaline?
- Chlorine kills organic matter by attacking it, right? How come the organic matter it's destabilizing doesn't create ionic salts that would make the water solution an undrinkable mess?
Etc.. Basically, every question/way I can think of for how water chlorination works gives me a question about how saltwater is stable.
(*) Spare the technically correct "Oh but it does [in ridiculously small quantities]" answer. I hope you understand what I'm getting at here.
Entropy is used in a lot of different ways by a lot of different physics. For most purposes it is a measurement of potential energy, as things give off energy as the grow more "disordered" and so it is used to calculate how much energy can be gotten out of a system.
Salt when dissolved releases one sodium and one chlorine. The compounds used in chlorinating pools and such is sodium hypochlorite (Na(ClO), this chlorine has an oxygen attached, and wants to get rid of it. So once the ionic bond is broken, it will oxidize organic matter which kills it.