Preparation Of Boric Acid

 Boric Acid:

             A mixture of concentrated sulphuric acid reacts with borax to form boric acid.

Na₂B₄O₇  +  H₂SO₄  +  5H₂O ———>      Na₂So₄          +          4H₃BO₃

                                                          ( Sodium sulfate )        ( Boric acid ) 

Boric acid can be extracted from colemanite. 

Ca₂B₆O₁₁  +  11H₂O₄  +  SO₂  ———>  Ca(HSO₃)₂  +  6H₃BO₃