State with equations what happens when borax is heated on a plantium wire loop and then to the resulting transparent mass a minute amount of CuO is added and the mixture is again heated first in an oxidising flame and then in the reducing flame of a Bunsen Burner .

Explanation

When borax is heated on a platinum wire loop a transparent glassy bead is formed
`Na_(2)B_(4)O_(7).10H_(2)O underset(-10H_(2)O) overset("heat")rarrNa_(2)B_(4)O_(7)overset("heat")rarr underset("Transparent glassy bead")ubrace("Sod.metaborate Boric anhydride")2NaBO_(2)+B_(2)O_(3)`
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)underset("flame") overset("Oxidising") (rarr)underset("Cupric metaborate (blue)")(Cu(BO_(2))_(2))`
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 cuprous metaborate and then to copper metal which produces a red colour.
`underset(("Blue"))underset("Cupric metaborate")(2Cu(BO_(2))_(2))+Crarr underset(("Colourless"))underset("Cuprous metaborate")(2CuBO_(2))+B_(2)O_(3)+CO`
`2CuNO_(2)Crarrunderset("Red")underset("Copper metal") (Cu)+B_(2)O_(3)+CO`