Which compound would you expect to have greater surface tension: acetone [(CH3)2CO] or water (H2O)? Explain.

Answer: Tension of water is higher than acetone.

Explanation

Intermolecular bonds between multiple water molecules are hydrogen bonds, since water has a hydrogen atom attached to an electronegative atom (oxygen), and that hydrogen atom binds to an oxygen atom from another water molecule.

An acetone molecule cannot make hydrogen bonds between its molecules because there is no hydrogen atom in its structure that is attached to one of the electronegative atoms, so the intermolecular bonds between two acetone molecules are dipole-dipole. Since hydrogen bonds are stronger than dipole-dipole interactions, the tension of water is higher than acetone because it is the strength of intermolecular forces that determines the surface tension. The tension of water is higher than acetone.