Question

Boric acid is polymeric due to:
A. Its acidic nature
B. The presence of hydrogen bonds
C. Its monobasic nature
D. Its geometry

Answer 1

Boric acid is composed of several hydroxyl groups. The presence of extensive hydrogen bonding in the compound leads to formation of a polymeric compound.

Complete step by step answer:
-Boric Acid is an inorganic compound composed of boron, hydrogen and oxygen with the chemical formula ${H_3}B{O_3}$. It is a monobasic Lewis acid. Boric acid is known by other names as acidum boricum, boracic acid, hydrogen borate and orthoboric acid.
-Boric acid appears as a white powder. It is completely soluble in water. It was first prepared by Wilhelm Homberg by the reaction of borax with hydrochloric acid. Boric acid is a compound of medicinal importance which possesses several properties like antiviral, antifungal, and antiseptic.
-In the molecule of boric acid the boron atom occupies the central position. The boric acid molecule contains three boron-oxygen single bonds between the boron atom and three hydroxyl groups. The structure of boric acid is trigonal planar.

The boric acid contains three hydroxyl groups. The electronegativity difference between the oxygen and hydrogen atoms makes the $O - H$ bond polar. Thus the hydrogen of one boric acid forms hydrogen bonding with the oxygen atoms of another boric acid molecule. The boric acid molecules exist in separate layers making a polymeric structure. The hydrogen atoms form covalent linkages with the $BO_3$ group of another molecule.
Hence option B is the correct answer, i.e. Boric acid is polymeric due to the presence of hydrogen bonds. The polymeric structure is not due to the acidic nature, monobasic nature or the geometry.

Note:
The hydrogen bonding is a strong force of attraction present within the molecule. The boric acid is not considered as a polymer. Only the structure of the compound is polymeric.