Question

If acetone has weaker IMF's in comparison to ethanol, why does it have greater surface tension?

Answer 1

Surface Tension
Surface tension is a measure of the toughness of the surface of a liquid
Stronger intermolecular forces → higher surface tension.

http://lessons.chemistnate.com/effects-of-intermolecular-forces.html

Answer 2

The IMFs of acetone are stronger..

Answer 3

@aaronq
How are they stronger? I thought ethanol was stronger...

Answer 4

They both have dipole-dipole IMF's right?

Acetone's dipole moment is 2.91 D while ethanol's is 1.69 D.

A greater dipole moment gives rise to stronger intermolecular forces.

Answer 5

I got the numbers from the wiki pages https://www.wikiwand.com/en/Acetone https://www.wikiwand.com/en/Ethanol

Answer 6

Here's the question I'm working on. Why is the viscosity of ethanol higher than acetone if acetone has stronger IMF's? I thoughthink that stronger IMF's = higher viscosity

Answer 7

Autocorrect :/
*thought

Answer 8

that's strange. the information you posted is different than what's on the wikipedia pages (which i trust, specially when they have citations).

Viscosity for acetone: 0.36 (10 °C), 0.295 cP (25 °C)

for ethanol: 0.0012 Pa s (at 20 °C), 0.001074 Pa s (at 25 °C)

It doesn't make sense for ethanol to be more viscous considering their IMFs.

Answer 9

Well, I just noticed that the formula for acetone is also incorrect in the table. Now that I look at the viscosity online, I think it makes more sense since the info provided was wrong.
I guess I'll have to confront my teacher with the inaccurate viscosities.
Thanks for the explanation @aaronq, I appreciate you helping

Answer 10

no problem! glad we got that sorted out