[LHM]

So when you have a mixture of two liquids like hexane and heptane, where the hexane-heptane intermolecular forces are similar to hexane-hexane and heptane-heptane intermolecular forces, the boiling point is in between their two boiling points. But what about something like acetone and water? Since the acetone-water intermolecular forces are now stronger than the acetone-acetone intermolecular forces at least, would that make the boiling point of the mixture higher than the boiling point of each separate liquid? Is there ever a time when the boiling point of the mixture is either higher than or lower than the boiling points of the liquids by themselves?

And kind of on a separate tangent, how do you know if a mixture is an azeotrope?

[Nobby]

So when you have a mixture of two liquids like hexane and heptane, where the hexane-heptane intermolecular forces are similar to hexane-hexane and heptane-heptane intermolecular forces, the boiling point is in between their two boiling points.

I dont think so. If so we could not seperate these compunds by destillation. But Oil a mixture of carbonhydrogen compounds will be seperated by destillation.

Mixture of water and alcohol and others will have a new boiling point what gives the azeotrop.

[LHM]

Mixture of water and alcohol and others will have a new boiling point what gives the azeotrop.

And others? How do you know which others?

[Nobby]

Organic Compounds with hetero atoms like Oxygen, Nitrogen, etc.

[Borek]

So when you have a mixture of two liquids like hexane and heptane, where the hexane-heptane intermolecular forces are similar to hexane-hexane and heptane-heptane intermolecular forces, the boiling point is in between their two boiling points.

Yes. And it is a function of the mixture composition. Vapor composition is different than the composition of the liquid, that allows separation by distillation.

But what about something like acetone and water? Since the acetone-water intermolecular forces are now stronger than the acetone-acetone intermolecular forces at least, would that make the boiling point of the mixture higher than the boiling point of each separate liquid? Is there ever a time when the boiling point of the mixture is either higher than or lower than the boiling points of the liquids by themselves?

Yes, thats an azeotrope, positive or negative.

And kind of on a separate tangent, how do you know if a mixture is an azeotrope?

Depends on the strength of the interactions between molecules. But in general it is hard to tell without experiment.