Question

When borax is heated strongly it gives:

• A. $B_2{O}_3$
• B. $N{a}_2{B}_4{O}_7$
• C. $NaB{O}_2+B_2{O}_3$
• D. None of the above

Answer 1

The correct option is C $NaB{O}_2+B_2{O}_3$

It first swells due to loss of water in the form of steam.
$N{a}_2{B}_4{O}_7\cdot 10H_{2}O\stackrel{\Delta }{⟶}N{a}_2{B}_4{O}_7\stackrel{\Delta }{⟶}2NaB{O}_2+B_2{O}_3$

$NaB{O}_2+B_2{O}_3$ is the glassy bead that is formed on heating borax. Hence correct option is c.