CHEMISTRY COMMUNITY

How do polarizability and the different intermolecular forces affect the boiling and melting points of compounds?

The stronger the intermolecular forces the higher the boiling point/melting point will be. Generally, polar molecules have dipole-dipole forces, making them have stronger intermolecular forces than nonpolar molecules, thus, they will boil/melt at a higher temperature.

The boiling point of H2S is -60 degrees C while the boiling point of H2O is 100 degrees C. These molecules are very similar in structure, but H2O is harder to break down because the bonds are stronger.

As intermolecular forces increase, the structure becomes more stable and therefore the melting/boiling points will also increase.

Jonathan Gong 1A wrote:The stronger the intermolecular forces the higher the boiling point/melting point will be. Generally, polar molecules have dipole-dipole forces, making them have stronger intermolecular forces than nonpolar molecules, thus, they will boil/melt at a higher temperature.

How do we find these intermolecular forces?

A stronger intermolecular force will have a greater boiling or melting point. This is because since the bonds are stronger, they are harder to break apart. Increasing the polarizability of a molecule will create a stronger interaction leading to a higher boiling and melting point.

Stronger bonds/interactions higher melting point

As the forces get stronger the BP and MPs get higher.