Formation of a green edged flame on igniting the vapours evolved by heating an inorganic salt with a few mL of ethyl alcohol and conc. `H_(2)SO_(4)` indicates the presence of :

Options

A. tartarate
B. oxalate
C. borate
D. acetate

Explanation

To solve the question regarding the formation of a green-edged flame upon igniting the vapors evolved from heating an inorganic salt with ethyl alcohol and concentrated sulfuric acid, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Reactants**: The question mentions an inorganic salt, ethyl alcohol (C2H5OH), and concentrated sulfuric acid (H2SO4).

2. **Select a Suitable Inorganic Salt**: A common inorganic salt that can be used in this reaction is sodium borate (Na3BO3), also known as borax.

3. **Reaction with Concentrated Sulfuric Acid**: When sodium borate is heated with concentrated sulfuric acid, it undergoes a reaction to form sodium sulfate (Na2SO4) and boric acid (H3BO3):
\[ \text{Na}_3\text{BO}_3 + \text{H}_2\text{SO}_4 \rightarrow \text{Na}_2\text{SO}_4 + \text{H}_3\text{BO}_3 \]

4. **Formation of Ethyl Borate**: The boric acid (H3BO3) produced in the previous step can then react with ethyl alcohol (C2H5OH) to form ethyl borate (C2H5)3BO3. This reaction can be represented as:
\[ \text{H}_3\text{BO}_3 + 3 \text{C}_2\text{H}_5\text{OH} \rightarrow (C_2H_5)_3\text{BO}_3 + 3 \text{H}_2\text{O} \]

5. **Observation of Flame Color**: The ethyl borate produced in this reaction is known to produce a green-edged flame when ignited. This is a characteristic of boron compounds.

6. **Conclusion**: Therefore, the formation of a green-edged flame indicates the presence of borate ions in the reaction mixture.

### Final Answer:
The presence of borate ions (specifically, ethyl borate) is indicated by the formation of a green-edged flame.

---