When dilute ferrous sulphate solution is added lto an aqueous solution containing nitrate ion followed by careful addition of concentrated sulphuric acid along the sides of test tube a ,brown ring is formed at the iterface between the solution and sulphuric acid layers .Which is anion is confined by the appearance of brown ring .What the conposition of the brown ring ?

Explanation

To solve the problem, we will break it down into steps:

### Step 1: Understanding the Reaction
When dilute ferrous sulfate (FeSO4) is added to a solution containing nitrate ions (NO3-), followed by the careful addition of concentrated sulfuric acid (H2SO4), a specific reaction occurs that leads to the formation of a brown ring at the interface of the two solutions.

**Hint:** Recall that ferrous ions can reduce nitrate ions under acidic conditions.

### Step 2: Identifying the Anion
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