The pBlock Elements - Result Question 8
####9. In borax bead test which compound is formed?
[2002]
(a) Ortho-borate
(b) Meta-borate
(c) Double oxide
(d) Tetra-borate
Show Answer
Solution:
(b) $Na_2 B_4 O_7 \cdot 10 H_2 O \xrightarrow[-10 H_2 O]{\Delta}$
$ \begin{aligned} & Na_2 B_4 O_7 \xrightarrow{\Delta} 2 NaBO_2+B_2 O_3 \\ & \text{ anhydrous } \quad \text{ sod.metaborate Boric anhydride } \\ & CuO+B_2 O_3 \longrightarrow \quad Cu(BO_2)_2 \\ & \text{ cupric meta borate(Blue beed) } \end{aligned} $
