Order bond strength from strongest to weakest (in aqueous solution): van der waals non-polar covalent bonds polar covalent bonds hydrogen bonds Ionic bonds
The Correct Answer and Explanation is:
In aqueous solution, the order of bond strength from strongest to weakest is:
- Ionic bonds
- Polar covalent bonds
- Hydrogen bonds
- Van der Waals non-polar covalent bonds
Explanation:
- Ionic Bonds: These bonds form between positively and negatively charged ions, and they are typically the strongest in aqueous solutions. In water, the ions dissociate and interact with water molecules through ion-dipole forces. The strength of ionic bonds in water is relatively high, given the large difference in electronegativity between the atoms involved. Water, being polar, effectively stabilizes these charges, making ionic bonds strong in aqueous environments.
- Polar Covalent Bonds: These occur when electrons are shared between atoms, but one atom has a greater electronegativity than the other, leading to a partial charge on each atom. In aqueous solutions, the difference in electronegativity allows for dipole-dipole interactions between water molecules and the polar molecules, stabilizing the bond and contributing to the overall strength. However, they are not as strong as ionic bonds because the charge is not as fully separated.
- Hydrogen Bonds: These are a type of dipole-dipole interaction where a hydrogen atom is covalently bonded to a highly electronegative atom (like oxygen or nitrogen) and interacts with another electronegative atom. While hydrogen bonds are weaker than ionic and polar covalent bonds, they are still quite strong in aqueous solutions. Water molecules form hydrogen bonds with each other, which is essential for many of water’s unique properties, such as its high boiling point and surface tension.
- Van der Waals Forces (Non-polar Covalent Bonds): These are the weakest of the interactions listed. Van der Waals forces are temporary, induced dipoles that occur in non-polar molecules. These forces arise due to the random movement of electrons which momentarily create transient dipoles. In aqueous solutions, they are weaker than all the other types of bonds because the interactions are not as stable and are easily disrupted.
This order reflects the strength of the bonds when dissolved in water, with ionic bonds being the strongest due to their full charge separation and van der Waals forces being the weakest due to their transient nature.
