Total number of lone pair of electrons in ` XeOF_4` is :

Options

A. 0
B. 1
C. 2
D. 3

Answer

To determine the total number of lone pairs of electrons in the molecule \( \text{XeOF}_4 \), we will follow these steps:

### Step 1: Identify the central atom
The central atom in the molecule \( \text{XeOF}_4 \) is xenon (Xe).

### Step 2: Determine the valence electrons
Xenon (Xe) is in Group 18 of the periodic table and has 8 valence electrons. Oxygen (O) is in Group 16 and has 6 valence electrons. Each fluorine (F) atom is in Group 17 and has 7 valence electrons. Since there are 4 fluorine atoms, they contribute a total of \( 4 \times 7 = 28 \) electrons.

### Step 3: Calculate the total number of valence electrons
The total number of valence electrons in \( \text{XeOF}_4 \) can be calculated as follows:
\[ \text{Total valence electrons} = \text{Valence electrons of Xe} + \text{Valence electrons of O} + \text{Valence electrons of 4 F} \]
\[ = 8 + 6 + 28 = 42 \text{ valence electrons} \]

### Step 4: Determine the number of bonding pairs
In \( \text{XeOF}_4 \), xenon forms one bond with oxygen and four bonds with the four fluorine atoms. Therefore, the number of bonding pairs is:
\[ \text{Bonding pairs} = 1 \text{ (Xe-O)} + 4 \text{ (Xe-F)} = 5 \text{ bonding pairs} \]

### Step 5: Calculate the number of lone pairs
Each bonding pair consists of 2 electrons. Therefore, the total number of electrons used in bonding is:
\[ \text{Electrons in bonding} = 5 \text{ bonding pairs} \times 2 = 10 \text{ electrons} \]
Now, we can calculate the number of electrons remaining for lone pairs:
\[ \text{Remaining electrons} = \text{Total valence electrons} - \text{Electrons in bonding} \]
\[ = 42 - 10 = 32 \text{ electrons} \]
Since each lone pair consists of 2 electrons, the number of lone pairs is:
\[ \text{Lone pairs} = \frac{32}{2} = 16 \text{ lone pairs} \]

### Step 6: Count the lone pairs on the central atom
However, only the xenon atom can have lone pairs. In the case of \( \text{XeOF}_4 \), xenon will have one lone pair left after forming 5 bonds.

### Final Answer
Thus, the total number of lone pairs of electrons in \( \text{XeOF}_4 \) is **1**.