Which of the statements given below is incorrect ?

Options

A. ONF is isoelectronic with `O_2N`
B. `OF_2` is an oxide of fluorine
C. `CI_2O_7` is an anhydride of perchloric acid
D. `O_3` molecule is bent

Answer

To determine which of the statements given is incorrect, we will evaluate each statement one by one.

### Step 1: Evaluate Statement A
**Statement A:** ONF is isoelectronic with O2N- (NO2-).

- **Count the electrons in ONF:**
- Oxygen (O) has 8 electrons.
- Nitrogen (N) has 7 electrons.
- Fluorine (F) has 9 electrons.

Total for ONF = 8 + 7 + 9 = 24 electrons.

- **Count the electrons in NO2-:**
- Nitrogen (N) has 7 electrons.
- Oxygen (O) has 8 electrons, and there are 2 oxygen atoms, so 2 x 8 = 16 electrons.
- The negative charge (-1) indicates one additional electron.

Total for NO2- = 7 + 16 + 1 = 24 electrons.

Since both ONF and NO2- have the same number of electrons (24), they are isoelectronic. Therefore, Statement A is **correct**.

### Step 2: Evaluate Statement B
**Statement B:** OF2 is an oxide of fluorine.

- **Determine the oxidation state of oxygen in OF2:**
- Fluorine (F) is more electronegative than oxygen, so it will have an oxidation state of -1.
- Let the oxidation state of oxygen be x. The equation becomes:

\( x + 2(-1) = 0 \)
\( x - 2 = 0 \)
\( x = +2 \)

Since the oxidation state of oxygen in OF2 is +2, it cannot be classified as an oxide (which requires an oxidation state of -2). Thus, Statement B is **incorrect**.

### Step 3: Evaluate Statement C
**Statement C:** Cl2O7 is an anhydride of perchloric acid.

- **Identify the relationship:**
- Perchloric acid (HClO4) can be formed from Cl2O7 by adding water:

\( Cl2O7 + H2O \rightarrow 2 HClO4 \)

Since Cl2O7 can produce perchloric acid upon hydration, Statement C is **correct**.

### Step 4: Evaluate Statement D
**Statement D:** O3 molecule is bent.

- **Analyze the structure of O3:**
- Ozone (O3) has a bent shape due to the presence of lone pairs on the central oxygen atom.
- The steric number is 3 (2 sigma bonds and 1 lone pair), leading to sp2 hybridization.

Therefore, the geometry is trigonal planar, but the shape is bent. Thus, Statement D is **correct**.

### Conclusion
The only incorrect statement among the options is **Statement B**: "OF2 is an oxide of fluorine."