The equivalent mass of nitrogen in nitrogen pentoxide is

Options

A. 12
B. 28
C. 2.8
D. 4.66

Explanation

To find the equivalent mass of nitrogen in nitrogen pentoxide (N₂O₅), we can follow these steps:

### Step 1: Determine the formula of nitrogen pentoxide
The formula of nitrogen pentoxide is N₂O₅.

### Step 2: Identify the oxidation state of nitrogen
Let’s assume the oxidation state of nitrogen is \( X \). In the compound N₂O₅, we have:

- 2 nitrogen atoms contributing \( 2X \)
- 5 oxygen atoms contributing \( 5 \times (-2) = -10 \)

Since the entire compound is neutral, we can set up the equation:

\[ 2X - 10 = 0 \]

### Step 3: Solve for the oxidation state of nitrogen
Rearranging the equation gives:

\[ 2X = 10 \]

\[ X = 5 \]

Thus, the oxidation state of nitrogen in N₂O₅ is +5.

### Step 4: Determine the N factor
The N factor for nitrogen in this case corresponds to its change in oxidation state. Since nitrogen goes from 0 (in elemental form) to +5 in N₂O₅, the N factor is 5.

### Step 5: Calculate the equivalent mass of nitrogen
The equivalent mass of an element is calculated using the formula:

\[ \text{Equivalent mass} = \frac{\text{Atomic mass}}{\text{N factor}} \]

The atomic mass of nitrogen (N) is approximately 14 g/mol. Therefore, we can calculate the equivalent mass of nitrogen as follows:

\[ \text{Equivalent mass of nitrogen} = \frac{14 \, \text{g/mol}}{5} \]

### Step 6: Perform the calculation
Calculating this gives:

\[ \text{Equivalent mass of nitrogen} = 2.8 \, \text{g/equiv} \]

### Final Answer
The equivalent mass of nitrogen in nitrogen pentoxide (N₂O₅) is **2.8 g/equiv**.

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