Question

Molecules are attracted to one another by Van der Waals forces. How do Van der Waals forces compare with ionic and covalent bonds?
A. Van der Waals forces are stronger than ionic and covalent bonds.
B. Van der Waals forces are weaker than ionic and covalent bonds.
C. Van der Waals forces are stronger than ionic bonds but weaker than covalent bonds.
D. Van der Waals forces are stronger than covalent bonds but weaker than ionic bonds.

Answer 1

Answer:

The answer is B. Van der Waals forces are weaker than ionic and covalent bonds.

Explanation:

In general, if we arrange these molecular forces from the strongest to weakest, it would be like this:

Covalent bonds > Ionic bonds > Hydrogen bonds > Dipole-Dipole Interactions > Van der Waals forces

Covalent bonds are known to have the strongest and most stable bonds since they go deep and into the inter-molecular state. A diamond is an example of a compound with this characteristic bond.

Ionic bonds are the next strongest molecular bond following covalent bonds. This is due to the protons and electrons causing an electro-static force which results to the strong bonds. An example would be Sodium Chloride (NaCl), which when separated is Na⁺ and Cl⁻.

Van der Waals forces, also known as Dispersion forces, are the weakest type of molecular bonds. They are only formed through residual molecular attractions when molecules pass by each other. It doesn't even last long due to the uneven electron dispersion. It can be made stronger by adding more electrons in the molecule. This kind of molecular bonds appear in non-polar molecules such as carbon dioxide.