Explain the reaction of borax on heating .

Explanation

Borax on heating loses water of crystallisation and swells to form a puffy mass which further heating melts to give a clear liquid which solidifies to a transparent glass like bead consist of sodium metaborate `( NaBO_(2))` and boric anhydride `B_(2) O_(3)` .
`Na_(2) B_(4)O_(7) : 10H_(2)O overset ("heat") to Na_(2) B_(4) O_(7) +10H_(2)O`
`Na_(2) B_(4) O_(7) overset("heat ")(rarr) underset ("Sodium meta borate ") (2NaBO_(2))+ underset("boric anhydride ") (B_(2)O_(3))`.