In the ring test of `NO_(3)^(-)` ion, `Fe^(2+)` ion reduces nitrate ion to nitric oxide, which combines with `Fe^(2+)` (aq) ion to form brown complex .
Write the reactions involved in the formation of brown ring.

Explanation

To understand the formation of the brown ring in the ring test for the nitrate ion (\(NO_3^-\)), we need to look at the reactions involved step by step.

### Step 1: Reduction of Nitrate Ion
The first step involves the reduction of the nitrate ion (\(NO_3^-\)) by ferrous ion (\(Fe^{2+}\)) in an acidic medium. The reaction can be represented as follows:

\[ NO_3^- + 3Fe^{2+} + 4H^+ \rightarrow NO + 3Fe^{3+} + 2H_2O \]
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