Chemistry

Problem

Borax Bead Test is carried out when the original mixture is coloured. It is done with the help of a clean platinum wire on which a small loop is made at the end. When borax is heated on platinum wire loop a transparent glass like bead is obtained. The hot bead is brought in contact with salt till it reacts with fused borax and colour is imparted to the bead. Bead colour is noted.

Colour of the bead	Ion
1. Blue green	$\text{Cu}^{2+}$
2. Yellow	$\text{Fe}^{3+}$
3. Green	$\text{Cr}^{3+}$
4. Violet	$\text{Mn}^{2+}$
5. Dark blue	$\text{Co}^{2+}$
6. Brown	$\text{Ni}^{2+}$

Glassy bead is of: a.

\text{B}_2\text{O}_3 + \text{NaBO}_2

\text{Na}_2\text{B}_4\text{O}_7 + \text{B}_2\text{O}_3

\text{NaBO}_2 + \text{Na}_3\text{BO}_3

\text{SiO}_2 + \text{B}_2\text{O}_3

Browse the problem library