In which of the following compounds, an elements exhibits two different oxidation states?

Options

A. `NH_(2)OH`
B. `NH_(4)NO_(3)`
C. `N_(2)H_(4)`
D. `N_(3)H`

Explanation

To determine in which of the given compounds an element exhibits two different oxidation states, we will analyze each compound step by step.

### Step 1: Analyze NH2OH (Hydroxylamine)
1. The compound is NH2OH.
2. The hydroxyl group (OH) has an oxidation state of -1.
3. Let the oxidation state of nitrogen (N) be \( x \).
4. The total oxidation state can be set up as:
\[ x + 2(+1) + (-1) = +1 \]
Simplifying this gives:
\[ x + 2 - 1 = +1 \implies x + 1 = +1 \implies x = 0 \]
5. Therefore, in NH2OH, nitrogen has an oxidation state of 0.

### Step 2: Analyze NH4NO3 (Ammonium Nitrate)
1. The compound is NH4NO3.
2. This can be split into two parts: NH4+ (ammonium) and NO3- (nitrate).
3. For NH4+, let the oxidation state of nitrogen be \( x \):
\[ x + 4(+1) = +1 \implies x + 4 = +1 \implies x = -3 \]
4. For NO3-, let the oxidation state of nitrogen be \( y \):
\[ y + 3(-2) = -1 \implies y - 6 = -1 \implies y = +5 \]
5. Thus, nitrogen in NH4NO3 exhibits two oxidation states: -3 in NH4+ and +5 in NO3-.

### Step 3: Analyze N2H4 (Hydrazine)
1. The compound is N2H4.
2. Let the oxidation state of nitrogen be \( x \):
\[ 2x + 4(+1) = 0 \implies 2x + 4 = 0 \implies 2x = -4 \implies x = -2 \]
3. Therefore, nitrogen in N2H4 has an oxidation state of -2.

### Step 4: Analyze N3H (Hydrazoic Acid)
1. The compound is N3H.
2. Let the oxidation state of nitrogen be \( z \):
\[ 3z + 1(+1) = 0 \implies 3z + 1 = 0 \implies 3z = -1 \implies z = -\frac{1}{3} \]
3. Therefore, nitrogen in N3H has an oxidation state of -1/3.

### Conclusion
From our analysis:
- **NH2OH**: Nitrogen = 0
- **NH4NO3**: Nitrogen = -3 (in NH4+) and +5 (in NO3-)
- **N2H4**: Nitrogen = -2
- **N3H**: Nitrogen = -1/3

The only compound where an element exhibits two different oxidation states is **NH4NO3**.

### Final Answer
**The compound in which an element exhibits two different oxidation states is NH4NO3.**

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