[sugaJ]

I'm stumped on this question. Ethylene glycol, or antifreeze has O-H groups and it seems like a fairly large molecule. Both of these usually increase viscosity so why does ethylene glycol have such a low viscosity?

Any help would be much appreciated.

Cheers

[lancenti]

You're going to need much more than polar interaction to make something viscuous.

Ethylene Glycol is just about as big as Ethanol, or maybe Propanol, so there isn't much ID-ID interaction going on. Since it has two -OH groups now, it just makes it something like, say, water (I'm obviously oversimplifying here).

To make it viscuous, you'll want a longer hydrocarbon chain - say maybe octane.