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State with equations what happens when borax is heated on a platinum wire Ioop and to the resulting transparent mass, a minute amount of `CuO` is added and the mixture is again heated first in the oxidising flame and then in the reducing flame of a Bunsen burner?

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When a borax is heated on a platinum wire loop, a transparent glassy beat called the borax bead is formed.
`Na_(2)B_(4)O_(7) . 10H_(2)Ounderset(-10H_(2)O)overset(Delta)toNa_(2)B_(4)O_(7)overset(740^(@)C)to ubrace(2NaBO_(2)+B_(2)O_(3))_("glassy mass");`
When this transparent glassy bead is heated with `CuO` in the oxidising flame, it imparts blue colour to the bead due to the formation of cupric metaborate.
`CuO + B_(2)O_(3) overset("oxidising flame")to Cu(BO_(2))_(2)`(blue bead)
However, when cupric metaborate is heated in the reducing flame of the Bunsen burner, the blue cupric metaborate is reduced by carbon present in the flame first to colourless coprous metaborate and then to metal which produces red scales.
`underset("Cupric metaborate")(2Cu(BO_(2))_(2))+C to underset("Cuprous metaborate")(2CuBO_(2)+B_(2)O_(3))+CO`
`overset(("blue"))(2CuBO_(2))+C to undersetunderset(("red"))("Copper metal")(2Cu overset(("Colourless"))(+)B_(2)O_(3))+CO`
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Borax Bead Test is carried out when the original mixture is coloured. It is done with the help of a cleam platinum wire on which a small loop is made at the end. When borax is heated on platinum wire loop 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",Cu^(2+)),(2." Yellow ",Fe^(3+)),(3." Green",Cr^(3+)),(4." Violet",Mn^(2+)),(5." Dark blue",Co^(2+)),(6." Brown",Ni^(2+)):} Q. The flame used in Borax Bead Test is:

Borax Bead Test is carried out when the original mixture is coloured. It is done with the help of a cleam platinum wire on which a small loop is made at the end. When borax is heated on platinum wire loop 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",Cu^(2+)),(2." Yellow ",Fe^(3+)),(3." Green",Cr^(3+)),(4." Violet",Mn^(2+)),(5." Dark blue",Co^(2+)),(6." Brown",Ni^(2+)):} Q. Glassy bead of :

Borax Bead Test is carried out when the original mixture is coloured. It is done with the help of a cleam platinum wire on which a small loop is made at the end. When borax is heated on platinum wire loop 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",Cu^(2+)),(2." Yellow ",Fe^(3+)),(3." Green",Cr^(3+)),(4." Violet",Mn^(2+)),(5." Dark blue",Co^(2+)),(6." Brown",Ni^(2+)):} Q. Blue bead can be of: