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ANOMALOUS PROPERTIES OF BORIC ACID

Boric acid is one of the weakest acidic compounds. Due to its features, it is used in various sectors. Learn what Boric acid, its uses, and synthesis are.

What Is Boric acid?

Boric acid, also known as Hydrogen Borate, is a weak acid. It is formed when the Borax reacts with hydrochloric acid. The molecular formula of Boric acid is H3BO3.

It is a colorless crystal that is mostly found in white powder form. Boric acid has no characteristic odor or smell of its own. It is soluble in water.

Boric acid is widely used for medical purposes. It acts as an antiseptic to treat minor wounds, cuts, and burns. Doctors and nurses also use it for medical dressing. It is also used as an insecticide, neutron absorber, and flame retardant.

Boric acid is also useful in eyewash and treatment of acne due to its antibacterial properties. The use of Boric acid is not limited to this. Boric acid is also available in powder form, used to avoid athlete’s foot. People spray Boric acid powder in the socks and shoes to avoid getting athlete’s foot.

Structure Of Boric Acid

Boric acid comes under the acidic chemical compound. It has four atoms of oxygen, three atoms, and one atom of phosphorus. Despite being a weak acid, it has other useful features. Antiviral, antiseptic, and antifungal properties make Boric acid a useful compound in several ways.

Boric acid is represented by the chemical formula H3BO3, where Boron is the central element. Boron belongs to the group 13 elements of the periodic table. In Boric acid, three hydroxyl group is attached to the Boron.

Boron undergoes sp2 hybridisation, whereas sp3 hybridisation occurs in Oxygen atoms. The boron atom contains 3 electrons in its valence shell, forming a sigma bond with three Oxygen atoms. The resultant molecule is trigonal planar in shape.

Synthesis Of Boric Acid

There are three ways to synthesize Boric acid.

  •       Using Borax
  •       Through Trihalides
  •       Diborane

Let us see how Boric acid is formed using each of the above ways.

1. Synthesis Of Boric Acid From Borax

Boric acid can be produced from Borax using any mineral acid, such as sulphuric or hydrochloric acid. After concentrating and chilling a mineral acid and Borax solution, Boric acid crystals form. As a result, Borax is the primary source of Boric acid production.

The following equation represents the production of Boric acid from Borax.

Na2B4O7.10H2O + 2HCl → 4H3BO3 + 5H2O + 2NaCl

Na2B4O7 + H2SO4 + 5H20 → 4H3BO3 + 5H2O + 2Na2SO4

2. Boric Acid Synthesis From Trihalides

Boron trihalides create Boric acid when exposed to water. We can make boric acid from boron tribromide, boron trichloride, and boron trifluoride, all boron trihalides. This is an example of a hydrolysis reaction.

The following equation represents the production of Boric acid from boron trihalides.

BX3 + 3H2O → B(OH)3 + 3HX

X can be any halogen atom (Fluorine, chlorine, or bromine)

3. Synthesis Of Boric Acid From Diborane

In the presence of water, diborane molecules create Boric acid. As a result of the hydrolysis reaction, diborane produces Boric acid and hydrogen gas.

The following equation represents the production of Boric acid from diborane.

B2H6 + 6H2O → 2B(OH)3 + 6H2

Anomalous Properties Of Boric Acid

Physical Properties

  •                 At room temperature, Boric acid is a colorless and odorless compound.
  •                 It is a white crystalline solid.
  •                 It is soluble in water.
  •                 The melting point of Boric acid is 170.9℃.
  •                 The boiling point of Boric acid is 300℃.
  •                 The molar mass is 61.83 g/mol.
  •                 It is slightly soluble in the solvent acetone.
  •                 It feels very soft to touch, just like soap.

Chemical Properties

  •       Boric turns into metaBoric acid at a temperature of 1700C.

H3BO3 170℃→ HBO2 + H2O

  •       When the temperature is at 2360C, it forms tetraBoric acid after dehydration.

4HBO2 →H2B4O7 + H2O

  •       When TetraBoric acid is heated again above 3300C, it forms Boron Trioxide.

H2B4O7 → 2B2O3 + H2O

  •       Boric acid forms trimethyl borate when it reacts with ethyl alcohol in concentrated sulphuric acid.

Uses Of Boric Acid

The list below points out some of the common use of Boric acid.

  1.     To neutralize the active hydrofluoric acid in fabricating textile fiberglass and the manufacture of flat panel displays.
  2.     Blacksmiths use it for welding flux and electroplating.
  3.     In the jewelry industry, as well as in the production of silly putty
  4.     It’s used as an insecticide and an antiseptic and antibacterial agent.
  5.     As a dry lubricant on the carrom boards.
  6.     A neutron poison is also used in some nuclear power reactors.
  7.     To keep grains like wheat and rice from spoiling.
  8.     In conjunction with guar gum, as a cross-linking and gelling agent. As a result, the viscosity and rheology of the drilling fluid are controlled.

Borax And Boric Acid

Borax and Boric acid are not different compounds. They are the same compound used to manufacture soaps and laundry products. Borax is extracted from Kernite, tourmaline, colemanite. It is then refined and used to manufacture laundry soaps.

Conclusion

Boric acid is popularly used to eliminate pests and insects at home and surrounding areas. It is commonly used as a pesticide in our everyday life. It also has its uses in the medical sector, where it is used as an antiseptic compound. It is helpful to treat small cuts, wounds, and infections. Nurses also use Boric acid as an antiseptic in dressings.