Assertion :- In `NH_(4)NO_(3)`, the oxidation number of the two N-atoms is not equal.
Reason :- One N atom is present in the ammonium ion while the other is present in the nitrate ion.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are False.

Answer

To solve the question regarding the oxidation states of nitrogen in ammonium nitrate (NH₄NO₃), we will follow these steps:

### Step 1: Identify the structure of NH₄NO₃
NH₄NO₃ is composed of two ions: the ammonium ion (NH₄⁺) and the nitrate ion (NO₃⁻).

### Step 2: Determine the oxidation state of nitrogen in the ammonium ion (NH₄⁺)
Let the oxidation state of nitrogen in NH₄⁺ be \( x \). The oxidation states of hydrogen are +1. Therefore, we can set up the equation based on the charge of the ion:

\[ x + 4(+1) = +1 \]

This simplifies to:

\[ x + 4 = 1 \]

Solving for \( x \):

\[ x = 1 - 4 = -3 \]

Thus, the oxidation state of nitrogen in the ammonium ion (NH₄⁺) is -3.

### Step 3: Determine the oxidation state of nitrogen in the nitrate ion (NO₃⁻)
Let the oxidation state of nitrogen in NO₃⁻ be \( y \). The oxidation states of oxygen are -2. Therefore, we can set up the equation based on the charge of the ion:

\[ y + 3(-2) = -1 \]

This simplifies to:

\[ y - 6 = -1 \]

Solving for \( y \):

\[ y = -1 + 6 = +5 \]

Thus, the oxidation state of nitrogen in the nitrate ion (NO₃⁻) is +5.

### Step 4: Compare the oxidation states of the two nitrogen atoms
From the calculations:
- The oxidation state of nitrogen in the ammonium ion (NH₄⁺) is -3.
- The oxidation state of nitrogen in the nitrate ion (NO₃⁻) is +5.

Since -3 is not equal to +5, we conclude that the oxidation numbers of the two nitrogen atoms in NH₄NO₃ are indeed not equal.

### Conclusion
The assertion that in NH₄NO₃, the oxidation number of the two nitrogen atoms is not equal is correct. The reason provided, that one nitrogen atom is in the ammonium ion while the other is in the nitrate ion, is also correct. Therefore, both the assertion and reason are true, and the reason correctly explains the assertion.

### Final Answer
Both assertion and reason are correct, and the reason is the correct explanation of the assertion.

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