Question

In borax bead test which compound is formed?

• A. Ortho borate
• B. Meta borate
• C. Double oxide
• D. Tetra borate

Answer 1

Answer: (B)

In borax bead test the coloured meta borates are
formed by transition metal salts.
$N{a}_2{B}_4{O}_7.10H_{2}O\underset{-10H_{2}O}{\overset{△}{\to }}N{a}_2{B}_4{O}_7$
$\stackrel{△}{\to }2NaB{O}_2+B_2{O}_3$
$B_2{O}_3+CuO⟶Cu(B{O}_2{)}_2$
Cupric m etaborate
(Blue bead)