/sci/ - Science & Math

>>15880268
There's no such thing as chemicals. They are a fiction pushed on us in school. You may as well ask
>How do we know what blackholes look like?
>How do we know what dinosaurs look like? Did they have feathers lol
They look like whatever you want them to look like.

>>15880277
But then how does chemistry work?

>>15880499
>Chemistry works
Proof?

That is a very broad question, wondering what the fuck you mean.

>>15880268
Crystallography

You can draw out the full structure if you have an H-NMR spectra for a molecule.

>>15880268
We use fancy equipment to look at them
You can predict the shape also, then confirm it later

>>15880268
Using analysis tools like crystallography, NMR, and IR Spectroscopy

>>15880268
Individual molecules are too small to "look" like anything. X-Ray and neutron crystallography give us the best information about the connectivity of the atoms in a molecule, but every picture you see on a screen is sort of an artist's rendition of blobs of electron density.

>>15880268
That is not a picture of what it looks like. That is a picture of how it behaves.

NMR
X-ray Crystallography
Atomic force microscopy
IR spectroscopy
Deuterium exchange Cryo-EM (for big molecules)

probably more techniques that I don't know about

>>15880500
When I add baking soda to vinegar it makes foam 100% of the time.

>>15880268
Atomic bonds are derived from how many electrons they have in their rings so it's possible to work out how many of what will stick to what else. This is how they did it before actually imaging them was possible.

>>15880687
>think molecule has +3/-3 bond
>actually has +3/-1 -2 bonds
>make mustard gas

>>15880268
We do not, scientists made up this crap in order to dupe people and steal their money.

>>15880268
We don't, we just know how they work (generally)

>>15880268
we know alcohol has an empirical formula of C2H6O, and we know it has to have an OH bond because of the reactions that produce it (e.g. hydration of ethene) and because we can measure the enthalpies of formation for various types of bond. We know its molecular weight because of how it acts in the gas phase.

>>15880268

>>15880268
NMR spectroscopy, mass spectroscopy, IR spectroscopy, geometrical mathematics (symmetry) applied to simple molecules to understand the general rules, "bond angle maximisation" theory as a result of electrostatic repulsion, and occasionally we can use electron microscopes or scanning tunnelling electron microscopes to see things directly

Disturb it with EM shit and see what happens. We can't know shit, we just guess.

We know in what order the atoms in a molecule are arranged by different analysis-methods such as NMR, IR, MS and several more i have no clue of.
These methods only give us the information about which atoms are next to each other/how are the covalent bonds arranged. With this information we can formulate a lewis formula. In order to really see molecules we can use scanning electron microscopes which work with the same principle as mircroscopes with visual light but with a beam of electrons which reduce the Abbe-Limit.
But its not too spectacular. It looks like a bunch of clouds in which you can guess the actual structure.

>>15880268
cum