Borate from green colour flame when burnt with (Conc. `H_2SO_4+` ethanol). Green colour flame is obtained due to due to formation of

Options

A. `(C_2H_5O)_3B`
B. `(C_2H_5)_2BO_3`
C. `(C_2H_5)_3B`
D. A and C are correct

Answer

To solve the question regarding the green color flame produced when borate is burnt with concentrated sulfuric acid (H₂SO₄) and ethanol, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The reactants in this reaction are borate (commonly represented as borax, Na₂B₄O₇), concentrated sulfuric acid (H₂SO₄), and ethanol (C₂H₅OH).

2. **Write the Reaction with Sulfuric Acid**: When borax is treated with concentrated sulfuric acid, it undergoes a reaction to produce boric acid (H₃BO₃) and sodium sulfate (Na₂SO₄). The balanced reaction can be written as:
\[ \text{Na}_2\text{B}_4\text{O}_7 + \text{H}_2\text{SO}_4 + 5\text{H}_2\text{O} \rightarrow \text{Na}_2\text{SO}_4 + 4\text{H}_3\text{BO}_3 \]

3. **Introduce Ethanol**: The boric acid produced can then react with ethanol to form triethyl borate. The reaction can be represented as:
\[ 4\text{H}_3\text{BO}_3 + 3\text{C}_2\text{H}_5\text{OH} \rightarrow \text{B}(\text{C}_2\text{H}_5)_3 + 3\text{H}_2\text{O} \]
Here, triethyl borate (B(C₂H₅)₃) is formed.

4. **Identify the Flame Color**: The green color flame is attributed to the presence of the boron compound, specifically the triethyl borate. When triethyl borate is burned, it produces a characteristic green flame.

5. **Conclusion**: Therefore, the green color flame observed is due to the formation of triethyl borate (C₂H₅)₃B.

### Final Answer:
The green color flame is obtained due to the formation of triethyl borate (C₂H₅)₃B.

---