The borax bead test the coloured ions give characteristic coloured beads due to formation of

Question

The borax bead test the coloured ions give characteristic coloured beads due to formation of (A) metal borates (B) metal metaborates (C) metal phosphates (D) metal tetraborates

Tardigrade Admin · Accepted Answer

Borax is widely used in qualitative analysis, since it gives coloured beads with transition
metal salts. The chemistry o f the borax bead test is as follows:

N a_{2} B_{4} O_{7} \cdot 10 H_{2} O \to N a_{2} B_{4} O_{7} + 10 H_{2} O

N a_{2} B_{4} O_{7} 74 0^{\circ}

2 N a B O_{2} + B_{2} O_{3}

Glassy bead sod. metaborate boric anhydride

C u S O_{4} + B_{2} O_{3} ⟶ C u O \cdot B_{2} O_{3} + S O_{3}

Thus coloured beads are formed due to the formation of metal metaborates.

Q. The borax bead test the coloured ions give characteristic coloured beads due to formation of

metal borates

metal metaborates

metal phosphates

metal tetraborates