So I have actually a pretty basic understanding of solubility, basically prefer dissolves like. Native my straightforward understanding that electronegativity and also molecule form acetone is a polar molecule, and also styrene, and I'm guessing native this polystyrene is non-polar. Ns googled this, and also I found something that claimed it was related to cohesive energy densities, and also that this term is concerned polarity, but I'm still confused. So my concern is why does acetone dissolve styrofoam as soon as they show up to be a mix of polar/non-polar? CP to ELI5

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level 1
· 5y
Styrofoam is consisted of of polystyrene foam. As soon as the polystyrene disappear in the acetone, the air in the foam is released, resulting in it to look prefer you're dissolving this huge quantity the material right into a tiny volume the liquid. You can see a less-dramatic version of the same result by dissolving various other polystyrene items in acetone. Usual polystyrene products include disposable razors, plastic yogurt containers, plastic mailers and cd jewel cases. The plastic disappear in just about any organic solvent, not just acetone. Acetone is discovered in part nail polish removers. If you can't find this product, you could dissolve styrofoam in gasoline just as easily.

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Taken directly from this website, thought it was a pretty an excellent explanation.

level 2
· 5y

you might dissolve styrofoam in gasoline

I love the odor of napalm in the morning!

level 2
Op · 5y

I appreciate your explanation, yet I was much more looking because that why that dissolves no how.

level 1
· 5y

TL;DR: it's entropic favored, no necessarily enthalpic.

like dissolves like

Well, this is where chemistry gets a tiny tricky, i do not care a 'case through case' study, and also starts having more exceptions come a dominance than noþeles else. 'Like disappear like' is a good rule that thumb, however should it is in approached v care.

As with most systems, this one will shot to minimize its total energy. For a simple dissolution like this, there room two contents that beat a most vital role, intermolecular bond energy and the system's entropy.

What you are thinking, about 'like dissolves like', is the ELI5 variation of the an initial part, to decrease intermolecular shortcut energy. I'll provide some an ext drastic and also easy to know examples, than come ago to acetone + polystyrene.

In a instance such together water + hydrocarbons (such together oil), they don't mix since the water-water interaction has much lower power than a water-hydrocarbon bond. Water-hydrocarbon shortcut (permanent dipole-induced dipole interaction) still has lower power than hydrocarbon-hydrocarbon (van der Waals), yet not reduced than water-water, so the mix won't happen.

For a mixture the ethanol and water, for example, castle mix due to the fact that the hydrogen bonding in water-ethanol is lot stronger 보다 in ethanol-ethanol, and also of comparable strength come water-water. This means that the power in the mixture is lower than because that the the separated compounds.

Things get amazing for salts. For example, for sodium chloride, you shouldn't really mean that it would dissolve in water. You room breaking ion-ion and hydrogen bonds to produce a dipole-ion bond. When ion-dipole bonds space strong, ion-ion (coulombic) room still stronger, and in fact, a salt chloride equipment has more energy than the be separate compounds. What drives dissolution, in this case, is the boost in entropy. Special, the ions in solution have many more ways to be arranged than in the hard state. This method that the solution has a 'higher disorder' (higher entropy), and is favored contrasted to the be separate compounds. This is additionally aided through the reality that the ion-dipole interaction, in this case, is of similar strength to the ion-ion and hydrogen bonds, for this reason the mechanism doesn't have actually to obtain too much energy in order to accomplish dissolution.

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This last case is indistinguishable to acetone + polystyrene. While acetone is polar, the partially hopeful carbon the the C=O link is hindered by the methyl (CH3) groups, such the the molecules' dipoles don't connect so strongly. Polystyrene additionally has weak intermolecular interaction (van der Waals). I'm not actually certain if the solution has actually a lower or higher energy 보다 the be separate compounds, yet in one of two people case, it must be close come zero, because acetone actually has an apolar part, and would interact quite well v the apolar chain of polystyrene. However just together in the case of NaCl, over there is a large increase in entropy upon dissolution, because the chains are now able to relocate much more freely.