Question

is hexane and acetone miscible?

Answer 1

nope

Answer 2

please explain why

Answer 3

Do you understand what miscible means?

Answer 4

I'm guessing this is for organic or some physical chemistry course that is organic based, at which you should try to come up with some explanation on your own first.

But, think about the \(inter\)molecular forces of each molecule.

Answer 5

The easy answer would be because hexane is non-polar and acetone is polar. Remember "like dissolves like." Hexane only have non-polar bonds (C-H doesn't have much dipole moment since the difference in their electronegativity is close to 0). Acetone has the C=O bond, and the oxygen tends to have much higher electronegativity, so you have a big dipole moment, therefore it's a polar molecule. A good general way to tell if an organic molecule will dissolve in polar solvents is by counting the number of oxygens that it has, one oxygen for every 3-5 carbon is a good indication that it'll dissolve.

The reason being why they don't mix well is because polar molecules have stronger intermolecular attractions (or IMF) toward other polar molecules (they also have IMF with non-polar molecules too but this tends to be weaker). This is why polar molecules tend to be attracted to other polar molecules and push the non-polar components away, so you have this separation of different layers.

This is too long of an answer but hope it'll answer most of your question

Answer 6

Although you're correct, in general, miscibility is used to describe liquids, since there is already a term for what you're describing - solubility.

For example, ethanol and water, yes, they are miscible (both being polar). But, if you mix water and say, occtyl alcohol or valeric acid, , or some biological macromolecule like a lipid it is not.