Consider the following reactions Na ₂ ~B ₄ O ₇ 2 X + Y CuSO ₄+ Y Non-Luminous flame Z + SO ₃ 2 Z +2 X + Carbon Luminous flame 2 Q + Na ₂ ~B ₄ O ₇+ CO The oxidation states of Cu in Z and Q, respectively are :

Step-by-step solution

The given reactions describe the Borax Bead Test. When borax ( Na₂B₄O₇ 10H₂O ) is heated, it first loses water and then melts to form a transparent glassy bead consisting of sodium metaborate ( NaBO₂ ) and boric anhydride ( B₂O₃ ). Na₂B₄O₇ 2NaBO₂ (X) + B₂O₃ (Y) In the non-luminous (oxidizing) flame, B₂O₃ reacts with CuSO₄ to form copper(II) metaborate ( Z ), which is blue in color. CuSO₄ + B₂O₃ Non-Luminous Cu(BO₂)₂ (Z) + SO₃ In Cu(BO₂)₂ , the oxidation state of Cu is +2 . In the luminous (reducing) flame, the copp