The compound formed in the borax bead test of `Cu^(2+)` in oxidising flame is

Options

A. Cu
B. `CuBO_(2)`
C. `Cu(BO_(2))_(2)`
D. none of these

Answer

**Step-by-Step Solution:**

1. **Understanding the Borax Bead Test**: The borax bead test is a qualitative analysis method used to identify certain metal ions based on the color changes observed in a borax bead when heated in a flame.

2. **Identifying the Metal Ion**: In this case, we are specifically looking at the behavior of copper ions (Cu²⁺) during the borax bead test.

3. **Heating the Borax Bead**: The borax bead, which is a mixture of borax (sodium borate) and water, is placed in a platinum wire loop and heated in the flame of a Bunsen burner. The flame can be oxidizing or reducing.

4. **Observing Color Changes**: When the borax bead containing copper ions is heated in an oxidizing flame, it undergoes a chemical reaction.

5. **Formation of the Compound**: The compound formed when Cu²⁺ ions are heated in an oxidizing flame is copper borate, specifically CuB₂O₄, which can also be represented as CuBO₂ whole twice (Cu₂B₂O₄).

6. **Color Observations**: In an oxidizing flame, the bead will exhibit a green color when hot and a blue color when cooled.

7. **Selecting the Correct Answer**: Among the options provided, the correct compound formed in the borax bead test for Cu²⁺ in an oxidizing flame is CuB₂O₄ (or CuBO₂ whole twice).

8. **Final Answer**: Therefore, the correct answer is option 3: CuBO₂ whole twice (Copper borate).

---