Number of moles of electrons take up when 1 mole of `NO_(3)^(-)` ions is reduced to 1 mole of `NH_(2)OH` is:

Options

A. 2
B. 4
C. 5
D. 6

Answer

To determine the number of moles of electrons that are taken up when 1 mole of \( \text{NO}_3^{-} \) ions is reduced to 1 mole of \( \text{NH}_2\text{OH} \), we can follow these steps:

### Step 1: Determine the oxidation state of nitrogen in \( \text{NO}_3^{-} \)
- In \( \text{NO}_3^{-} \), each oxygen has an oxidation state of -2.
- Let the oxidation state of nitrogen be \( x \).
- The total charge of the ion is -1, so we can set up the equation:
\[ x + 3(-2) = -1 \]
\[ x - 6 = -1 \]
\[ x = +5 \]
- Therefore, the oxidation state of nitrogen in \( \text{NO}_3^{-} \) is +5.

### Step 2: Determine the oxidation state of nitrogen in \( \text{NH}_2\text{OH} \)
- In \( \text{NH}_2\text{OH} \), let the oxidation state of nitrogen be \( y \).
- The two hydrogens contribute +2, and the oxygen contributes -2. The total charge is 0, so we set up the equation:
\[ y + 2 - 2 = 0 \]
\[ y = -1 \]
- Therefore, the oxidation state of nitrogen in \( \text{NH}_2\text{OH} \) is -1.

### Step 3: Calculate the change in oxidation state
- The change in oxidation state for nitrogen from \( \text{NO}_3^{-} \) to \( \text{NH}_2\text{OH} \) is:
\[ \text{Change} = \text{Final state} - \text{Initial state} = (-1) - (+5) = -6 \]
- This indicates that nitrogen is reduced by 6 units.

### Step 4: Determine the number of moles of electrons involved
- Each unit change in oxidation state corresponds to the transfer of one mole of electrons. Therefore, a change of -6 means that 6 moles of electrons are taken up during the reduction process.

### Conclusion
- The number of moles of electrons taken up when 1 mole of \( \text{NO}_3^{-} \) is reduced to 1 mole of \( \text{NH}_2\text{OH} \) is **6 moles**.