Shape and hybridisation of `SO_2` are

Options

A. V shape, sp
B. triangular planar, `sp^2`
C. V shape, `sp^2`
D. tetrahedral, `sp^2`

Answer

To determine the shape and hybridization of the molecule \( SO_2 \) (sulfur dioxide), we can follow these steps:

### Step 1: Identify the central atom and its valence electrons
The central atom in \( SO_2 \) is sulfur (S). Sulfur belongs to group 16 of the periodic table, which means it has 6 valence electrons.

**Hint:** Remember that the number of valence electrons can be found based on the group number of the element in the periodic table.

### Step 2: Determine the bonding in the molecule
In \( SO_2 \), sulfur is bonded to two oxygen atoms. Each sulfur-oxygen bond is a double bond, which consists of one sigma bond and one pi bond. Therefore, for the two double bonds, we have:

- 2 sigma bonds (one from each double bond)
- 2 pi bonds (one from each double bond)

**Hint:** A double bond consists of one sigma bond and one pi bond. Count only the sigma bonds when determining the steric number.

### Step 3: Count the lone pairs on the central atom
Since sulfur has 6 valence electrons and it uses 4 electrons (2 electrons for each sigma bond), it has 2 electrons left. These 2 electrons will form one lone pair.

**Hint:** After accounting for the bonding electrons, subtract from the total valence electrons to find the number of lone pairs.

### Step 4: Calculate the steric number
The steric number is calculated using the formula:
\[ \text{Steric Number} = \text{Number of Sigma Bonds} + \text{Number of Lone Pairs} \]
In \( SO_2 \):
- Number of sigma bonds = 2 (from the two double bonds)
- Number of lone pairs = 1

Thus, the steric number is:
\[ \text{Steric Number} = 2 + 1 = 3 \]

**Hint:** The steric number helps determine the hybridization and geometry of the molecule.

### Step 5: Determine the hybridization
For a steric number of 3, the hybridization of the central atom (sulfur) is \( sp^2 \).

**Hint:** Familiarize yourself with the relationship between steric number and hybridization (e.g., steric number 2 = sp, 3 = sp², 4 = sp³).

### Step 6: Determine the molecular geometry
The geometry corresponding to \( sp^2 \) hybridization is trigonal planar. However, because there is one lone pair, the actual shape of the molecule will be bent or V-shaped.

**Hint:** The presence of lone pairs affects the molecular shape but not the electron geometry.

### Step 7: Finalize the shape and hybridization
Thus, the shape of \( SO_2 \) is V-shaped (or bent), and the hybridization of sulfur in \( SO_2 \) is \( sp^2 \).

**Final Answer:** The shape of \( SO_2 \) is V-shaped (or bent), and its hybridization is \( sp^2 \).