Boric acid is only accept OH- and does not donate H+ so it not donar of H+ even it is acid..

Boric acid (H3BO3) is a compound that behaves as a Lewis acid in aqueous solution. To understand why boric acid is considered a Lewis acid, let's first define the different types of acids.

Arhenius Acid:
An Arhenius acid is a substance that donates hydrogen ions (H+) when dissolved in water. These acids increase the concentration of H+ ions in the solution. However, boric acid does not ionize completely in water and does not produce a high concentration of H+ ions. Therefore, it is not considered an Arhenius acid.

Bronsted Acid:
A Bronsted acid is a substance that donates a proton (H+) to another substance. In aqueous solution, boric acid can donate a proton to water, acting as a weak acid. However, this alone does not fully explain its behavior.

Lewis Acid:
A Lewis acid is a substance that accepts a pair of electrons during a chemical reaction. Boric acid has an empty p-orbital on the boron atom, which can accept a pair of electrons from a Lewis base. In solution, boric acid can accept a lone pair of electrons from a water molecule, forming a coordinate covalent bond. This behavior makes it a Lewis acid.

Explanation:
Boric acid, H3BO3, is a weak acid that partially ionizes in water. In aqueous solution, it can accept a pair of electrons from a water molecule, forming a complex ion called a tetrahedral borate ion (B(OH)4-). This reaction can be represented as follows:

H3BO3 + H2O → B(OH)4- + H3O+

Here, the boron atom in boric acid accepts a pair of electrons from a water molecule, making it a Lewis acid. The formation of the tetrahedral borate ion is evidence of its Lewis acidic behavior.

Conclusion:
In summary, boric acid is considered a Lewis acid in aqueous solution because it can accept a pair of electrons from a water molecule, forming a coordinate covalent bond. It does not fully ionize like Arhenius acids, and while it can donate a proton like a Bronsted acid, its Lewis acid behavior is more prominent. Therefore, the correct option is C) Lewis acid.