Provide an example of the enthalpy of fusion of different molecules and the strength of their intermolecular forces.

The enthalpy of fusion varies with the strength of intermolecular forces between molecules.

The enthalpy of fusion is the amount of energy required to melt a solid and turn it into a liquid at its melting point. This energy is used to overcome the intermolecular forces between the molecules in the solid. The strength of these forces depends on the type of molecule and its structure.

For example, water has a high enthalpy of fusion because it has strong hydrogen bonds between its molecules. These bonds are electrostatic attractions between the positively charged hydrogen atoms of one molecule and the negatively charged oxygen atoms of another. These bonds are relatively strong, so it takes a lot of energy to break them and melt the ice.

In contrast, methane has a low enthalpy of fusion because it has weak van der Waals forces between its molecules. These forces are caused by temporary dipoles in the electron clouds of the molecules, which attract each other. These forces are relatively weak, so it takes less energy to break them and melt the solid.

Overall, the enthalpy of fusion is a useful measure of the strength of intermolecular forces between molecules. It can be used to predict the melting and boiling points of substances, as well as their physical properties such as viscosity and surface tension.