Chemical 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. 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. Boric acid is weak acid properties with pH = 9.2, which not uses as protons donor but as a lewis acid with accepting pair of the electron from the hydroxyl ion.

Boric acid (H3BO3) Structure, Properties, Preparation, and Chemical uses


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

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 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. H3BO3 acts as a strong acid in anhydrous H2SO4 solution.
  • Treatment of H3BO3 with sodium peroxide or hydrogen peroxide sodium or mono peroxo-borates obtained in the solution with the bridging μ-peroxo group.

Uses of Boric Acid Powder

Boron and boric acid extensively use in the modern age as reinforcement materials in space shuttles and aircraft.

  1. It uses in medicine as an antiseptic and antibacterial.
  2. It uses in the textile chemical industry for making borosilicate glass.
  3. For the preparation of enamels, we use largely H3BO3 and borax powder.
  4. Sodium perborate which prepared from H3BO3, uses for detergent preparation.
  5. Boric acid uses for the preservation of grains like wheat and rice from the insecticides.
  6. Boron carbides and metal borides extensively used as neutrons shielding chemical and control rods in nuclear plants.