Final answer:
Boric acid undergoes chemical changes with heat, resulting in metaboric acid, tetraboric acid, and boric oxide. The boron atom is sp² hybridized in boric acid, and borates exhibit structural diversity and practical uses. Water's chemical bonding is crucial in this process and for understanding solvency and reaction behaviors.
Step-by-step explanation:
The behavior of boric acid under thermal conditions involves various chemical transformations. At 100 °C, boric acid loses water molecules to form metaboric acid, HBO2. As the temperature increases to about 150 °C, more B-O-B linkages are formed, resulting in the creation of tetraboric acid, H2B4O7. Eventually, upon complete dehydration at even higher temperatures, boric oxide is produced. Furthermore, the boron atom in boric acid, B(OH)3, is sp2 hybridized and assumes a trigonal planar structure. This molecule can act as a Lewis acid by accepting an electron pair and exhibits the ability to form hydrogen bonds in its solid state.
In contrast, water molecules are held together by chemical bonds, specifically polar covalent bonds, which result in water's unique properties such as high solvency and the ability to form hydrogen bonds. Water chemistry is essential for understanding the solubility and behavior of various substances, including borates and the hydrolysis reactions of boron trihalides. Borates, being salts of oxyacids of boron, show a structural diversity ranging from simple ions to complex chains and rings, and have practical uses, such as in laundry detergents with borax being a commonly used borate.