In which of the following N-N bond is not present ?

Options

A. `N_(2) O_(5)`
B. `N_(2) O`
C. `N_(2) O_(4)`
D. `N_(2) O_(3)`

Answer

To determine in which of the following compounds the N-N bond is not present, we will analyze the molecular structures of each compound: N2O5, N2O, N2O4, and N2O3.

### Step 1: Analyze N2O5 (Dinitrogen Pentoxide)
- **Structure**: N2O5 consists of two nitrogen atoms bonded to five oxygen atoms. The structure can be visualized as:
- N=O
- N-O
- O
- O
- O
- **Bonding**: In N2O5, the nitrogen atoms are connected to oxygen atoms, and there is no direct N-N bond present.

### Step 2: Analyze N2O (Dinitrogen Monoxide)
- **Structure**: N2O consists of two nitrogen atoms and one oxygen atom. The structure can be represented as:
- N≡N
- O
- **Bonding**: In N2O, there is a triple bond between the two nitrogen atoms, indicating the presence of an N-N bond.

### Step 3: Analyze N2O4 (Dinitrogen Tetroxide)
- **Structure**: N2O4 consists of two nitrogen atoms and four oxygen atoms. The structure can be represented as:
- N-N
- O=O
- O
- **Bonding**: In N2O4, there is a direct N-N bond between the two nitrogen atoms.

### Step 4: Analyze N2O3 (Dinitrogen Trioxide)
- **Structure**: N2O3 consists of two nitrogen atoms and three oxygen atoms. The structure can be represented as:
- N-N
- O
- O
- **Bonding**: In N2O3, there is also a direct N-N bond between the two nitrogen atoms.

### Conclusion
After analyzing all four compounds, we find that:
- N2O5 does not contain an N-N bond.
- N2O, N2O4, and N2O3 all contain N-N bonds.

Thus, the answer is **N2O5**.