Question

Which one of the following methods is used to prepare borax crystals?

विकल्प

• A hot conc. solution of B₂O₃ is made to react with calculated quantity of conc. H₂SO₄ 

• Tincal is dried up and heated to red heat 

• Tincal is powdered, treated with water and evaporated 

• An alcoholic solution of boric acid is evaporated and cooled.

Answer 1

An alcoholic solution of boric acid is evaporated and cooled.

Explanation:

It is prepared by natural tincal which is highly soluble in hot water. 

The insoluble impurities filtered off and solution is concentrated and cooled, the crystal Borax is obtained.