Hydrogen bonding is a type of intermolecular force that occurs between molecules containing hydrogen atoms bonded to highly electronegative elements such as nitrogen, oxygen, or fluorine. The strength of hydrogen bonding is intermediate between Vander Waals and covalent bonds. Let's understand this statement in detail.

Vander Waals forces
Vander Waals forces are weak intermolecular forces that arise due to the fluctuating electron density around atoms and molecules. These forces include London dispersion forces, dipole-dipole interactions, and hydrogen bonding. The strength of Vander Waals forces depends on the size and shape of the molecules, the number of electrons, and the distance between them. Vander Waals forces are the weakest of all intermolecular forces.

Covalent bonds
Covalent bonds occur when two atoms share electrons to form a stable molecule. These bonds are strong and require a significant amount of energy to break. The strength of covalent bonds depends on the electronegativity and size of the atoms involved in the bond.

Hydrogen bonding
Hydrogen bonding occurs when a hydrogen atom bonded to a highly electronegative atom such as nitrogen, oxygen, or fluorine, interacts with another electronegative atom in a different molecule. This interaction results in a strong dipole-dipole attraction between the two molecules. Hydrogen bonding is stronger than Vander Waals forces but weaker than covalent bonds.

Conclusion
In conclusion, the strength of hydrogen bonding is intermediate between Vander Waals and covalent bonds. This is because hydrogen bonding involves dipole-dipole interactions like Vander Waals forces but the electronegativity difference between the hydrogen atom and the electronegative atom creates a partial covalent bond between the two atoms. Therefore, hydrogen bonding has a strength that is intermediate between Vander Waals and covalent bonds.