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Belonging to the family of Boron in the p-Block
elements group, Borax is a compound white in color. It occurs as a mineral in the salt deposits. It can be used in antiseptic medicines, used for making glass and ceramics, used in detergent powders, house cleaners and as a metallurgical flux. Also known as sodium borate, is powder. The anomalous properties of Borax are higher melting point, metalloid composition and more.
What is Borax?
A white coloured substance that is powdery in its consistency is Borax. It belongs to the family of Boron. It consists of a combination of Boron, water and sodium. It is found as a mineral that is left behind after the water at the valleys evaporates. It has crystals that are colorless. The Borax substance sold in the markets is somewhat dehydrated. Borax has various forms like anhydrous, pentahydrate, decahydrate salts. It also dissociates itself into sodium hydroxide, which is a strong base and boric acid, which is a weak acid. It is basic or alkaline in nature. When Borax is heated, the properties of Borax changes, and it gets transformed into Borax beads. However, the properties of Borax are anomalous or exceptional. This is because it belongs to the Boron, which is the first element of the group, and so it is different.
Borax has many different formulae, and these formulae depend on its crystallization of water.
All formulae are given below –
Sodium Tetraborate – Na2B4O7
Sodium Tetraborate Pentahydrate – Na2B4O7·5H2O
Sodium Tetraborate Octahydrate – Na2[B4O5(OH)4]·8H2O
Sodium Tetraborate Decahydrate – Na2B4O7.10H2O
Physical Properties of Borax
Molar Mass | Anhydrous – 201.22 Decahydrate – 381.38 |
|---|---|
Appearance | White Powder, Solid |
Density | Anhydrous, Solid – 2.4 g/cm3 Decahydrate, Solid – 1.73 g/cm3 |
Melting Point | 743 degrees – Anhydrous 75 degrees – Decahydrate |
Boiling Point | 1575 degrees |
Solubility in Water | 31.7 g/L for both anhydrous and decahydrate |
Magnetic Susceptibility | -85.0·10-6 cm3/mol |
Chemical Properties of Borax
All the compounds of the family of Boron, in which Borax is one, have almost the same chemical properties. The chemical properties of Borax are listed in the table given below.
Acid Reaction | Borax is a compound that does react with acids. After the reaction, the properties of Borax change. It transforms into an acid called Boric acid. Boric acid is a substance that comes into many uses. The reaction is as follows – Na2B4O7ᐧ10H2O+2HCl→4B(OH)3 + 2NaCl + 5H2O |
Ability to burn | Borax is a substance that can easily be burnt. Hence it falls into the category of flammable substances. At burning, the color of the flame becomes yellow-green. |
Solubility | Borax has a high solubility in ethylene glycol, whereas its solubility in acetone is comparatively less. |
Sodium Hydroxide Reaction | On reacting Borax with sodium hydroxide, the formation of a new compound is named Sodium Metaborate. The reaction is given below – Na2B4O7 + 2NaOH → 4NaBO2 + H2O |
The Anomalous Properties of Borax
The first element of every family has properties that are very different from all the other elements. Boron, the first element of the family, also has exceptional properties. Since Borax belongs to the family of Boron, Borax has anomalous properties too. The list is as follows –
High melting point, high boiling point
It is non-metallic in nature
Comparatively less covalency
Trihalides in monomeric form
The oxide formed has an acidic nature
Forms covalent compounds
D-orbital is absent
The Uses of Borax
Borax can be used in numerous ways, both in households and in the medical field. However, increased exposure to Borax can cause serious problems. The list of its uses is as follows –
There are many such properties of Borax that make it a cleaning agent. It is used in detergents and floor cleaners.
A unique use of Borax is as an insect killer.
It also serves in the medical field as it is used to test Mellitus diabetes.
It is used in the welding of iron.
It is also found in cosmetics, toothpaste and mouthwash.
It is also used in paints.
It is also used to make slime.
The Structure and Occurrence of Borax
Borax is found mainly in the areas where the lake beds have been dried out. A few places are Death Valley in California, Turkey, Tibet, Chile, Italy and more. When the heat of the sun falls on the ground, the water evaporates. It is after evaporation that the mineral deposits are formed. Borax is found in these mineral deposits. As far as the structure is concerned, there are two Boron atoms that are present in the triangular form, while the other two Boron atoms are in tetrahedral form. Borax consists of units that are tetranuclear- (B4O5(OH)4)2-.
Conclusion
Borax belongs to the family of Boron. It is a white coloured powdery substance. When it is crystallized with water, the chemical composition of Boron changes. It can easily be burnt, and on reaction, it changes into Boric acid. Behavior of Borax is anomalous in nature due to its non-metallic nature and high melting and boiling points. Its boiling point is as high as 1575 degrees. When Borax oxidizes, it becomes acidic in nature. It has multiple household uses – cleaning agent, cosmetics, disinfectant, used in mouthwashes and toothpaste. It is also used for testing Mellitus diabetes. Borax is found in areas like Chile, California, Italy and more.
