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 the oxidation states of nitrogen in each compound provided in the options.

### Step-by-Step Solution:

1. **Identify the Compounds**: We are given four nitrogen-containing compounds to analyze. Let's denote them as:
- (1) NH2OH (Hydroxylamine)
- (2) Ammonium Nitrate (NH4NO3)
- (3) N2H4 (Hydrazine)
- (4) N3H (Azide)

2. **Calculate Oxidation State for NH2OH**:
- Let the oxidation state of nitrogen be \( X \).
- The oxidation state of hydrogen is +1 (4 hydrogen atoms contribute +4).
- The hydroxyl group (OH) has a charge of -1.
- The overall charge of the molecule is 0.
- Thus, we set up the equation:
\[ X + 4 - 1 = 0 \implies X = -1 \]
- Therefore, nitrogen in NH2OH has an oxidation state of -1.

3. **Calculate Oxidation State for Ammonium Nitrate (NH4NO3)**:
- For the ammonium ion (NH4+):
- Let the oxidation state of nitrogen be \( X \).
- The equation becomes:
\[ X + 4 - 1 = 0 \implies X = -3 \]
- For the nitrate ion (NO3-):
- Let the oxidation state of nitrogen be \( Y \).
- The equation becomes:
\[ Y - 6 = -1 \implies Y = +5 \]
- Thus, nitrogen in ammonium exhibits -3 and in nitrate exhibits +5. This means nitrogen in ammonium nitrate has two different oxidation states.

4. **Calculate Oxidation State for N2H4**:
- Let the oxidation state of nitrogen be \( X \).
- The equation becomes:
\[ 2X + 4 = 0 \implies 2X = -4 \implies X = -2 \]
- Both nitrogen atoms in N2H4 have the same oxidation state of -2.

5. **Calculate Oxidation State for N3H**:
- Let the oxidation state of nitrogen be \( Z \).
- The equation becomes:
\[ 3Z + 1 = 0 \implies 3Z = -1 \implies Z = -\frac{1}{3} \]
- All three nitrogen atoms in N3H have the same oxidation state of -1/3.

6. **Conclusion**:
- From the calculations, we find that only in ammonium nitrate (NH4NO3) does nitrogen exhibit two different oxidation states: -3 in the ammonium ion and +5 in the nitrate ion.
- Therefore, the answer is **Ammonium Nitrate (NH4NO3)**.

### Final Answer:
The compound in which an element exhibits two different oxidation states is **Ammonium Nitrate (NH4NO3)**.