The concept of Lewis acids and bases focuses on which of the following?

The concept of Lewis acids and bases is centered around the transfer of electrons. In this framework, a Lewis acid is defined as a species that can accept an electron pair, while a Lewis base is a species that can donate an electron pair. This definition expands the concept of acid-base reactions beyond just proton transfer, which is the focus of the Brønsted-Lowry theory.

In Lewis acid-base interactions, the bonding occurs through the sharing of electron pairs, which can lead to the formation of coordinate covalent bonds. For example, when ammonia (a Lewis base) donates a pair of electrons to boron trifluoride (a Lewis acid), a stable adduct is formed. This highlights the key role that electron exchange plays in these acid-base reactions and demonstrates how they can occur in various contexts, including organic and inorganic chemistry.

The other concepts presented, such as the transfer of protons or the formation of ionic bonds, are not aligned with the Lewis definition. Similarly, solubility in water is not directly related to the Lewis theory and instead pertains to the interactions of substances with water molecules and the concept of polarity.