Properties of Boric Powder
Boric acid or Boric Powder chemical formula of H3BO3 is the end product of hydrolysis of boron halides and hydrides. Boric powder commonly get by acidifying and heating borax solution in chemistry. The shining white crystals structure of boric acid contains B(OH)3 linked by hydrogen bonding in infinite layers of hexagonal symmetry and moderately soluble in water solution.
The conductance of the aqueous solution of boric acid is very weak and enhanced by the addition of polyhydric alcohol like mannitol, glycerol, etc. Therefore, the strength of this acid now increases and possible to reiterate the base solution using phenolphthalein as an indicator. This reaction also is known as the borax phenolphthalein test of glycerol in learning chemistry or organic chemistry.
Preparation of H3BO3
Boric acid obtained by boiling borax with acids and then crystallizing. The acid also produced during the hydrolysis reaction of boron halides.
Na2B4O7(OH)4 + 2HCl + 3H2O → 4H3BO3 + 2NaCl
BCl3 + 3H2O → H3BO3 + 3HCl
Properties of Boric Acid Solution
Dilute aqueous boric acid solution contains mononuclear species but various polymeric ions formed in concentrated chemical solution depending on the pH scale, concentration, and temperature. At 100°C, the acid changed to metaboric acid (HBO2), at 140°C to pyroboric acid, and finally at the higher temperature to B2O3.
- With earthy alcohol in the presence of sulfuric acid alkyl borate is formed and this reaction uses for quantitative chemical analysis of borates and H3BO3.
H2BO3 + 3C2H5OH → B(OC2H5)3 + 3H2O
- On fusion with metal oxides colored borate glasses formed and with NH4HF2 ultimately BF3 obtained. Therefore, H3BO3 acts as a strong acid in anhydrous sulfuric or nitric acid solution.
- Treatment of H3BO3 with sodium peroxide or hydrogen peroxide gives sodium or mono peroxo-borates. Hence the structure of peroxoborate ion is [B2(O2)2(OH)4]-2 in which two tetrahedral sp3 hybridized orbitals of boron bonding by bridging μ-peroxo groups.
Uses of Boric Acid Powder
Boron and boric acid extensively use in the modern age as reinforcement materials in space shuttles and aircraft.
- It an antiseptic and antibacterial. Therefore. it uses largely in medicine.
- It uses in the textile chemical industry for making borosilicate glass.
- For the preparation of enamels of our teeth, we use shining H3BO3 and borax powder.
- Sodium perborate which prepared from H3BO3, uses for detergent preparation in the chemical industry.
- Boric acid uses for the preservation of grains like wheat and rice from the insecticides.
- Boron carbides and metal borides extensively used as neutrons shielding chemical and control rods in nuclear plants.