Question

hich molecules would most likely cause a liquid to have the lowest viscosity?
large, polar molecules
small, nonpolar molecules
small, polar molecules
large, nonpolar molecules

Answer 1

Small, nonpolar molecules.

Reason: lowest viscosity occurs when molecules are small (less entanglement and lower friction) and have weak intermolecular forces. Nonpolar molecules only have weak dispersion forces, whereas polar molecules (especially those that hydrogen bond) have stronger attractions that raise viscosity.