The geometry of `ClO_(3)^(-)` ion according to valence shell electron pair repulsion (VSEPR) theory will be :

Options

A. Planar triangular
B. Trigonal Pyramidal
C. Tetrahedral
D. Square planar

Answer

To determine the geometry of the \( \text{ClO}_3^{-} \) ion according to the Valence Shell Electron Pair Repulsion (VSEPR) theory, we can follow these steps:

### Step 1: Determine the total number of valence electrons
- Chlorine (Cl) has 7 valence electrons.
- Each oxygen (O) has 6 valence electrons, and there are three oxygens, contributing \( 3 \times 6 = 18 \) valence electrons.
- The ion carries a negative charge (-1), which adds one more electron.

**Total valence electrons = 7 (from Cl) + 18 (from 3 O) + 1 (negative charge) = 26 valence electrons.**

### Step 2: Draw the Lewis structure
- Place Cl in the center and connect it to three O atoms.
- Two of the O atoms will form double bonds with Cl, and one O will have a single bond.
- After forming these bonds, we need to account for the remaining electrons.

**Double bonds consume 4 electrons (2 for each double bond), and the single bond consumes 2 electrons. Thus, 6 electrons are used for bonding.**

**Remaining electrons = 26 - 6 = 20 electrons.**

- Distribute the remaining electrons to satisfy the octet rule for the O atoms. The single-bonded O will take 6 electrons (3 lone pairs), while each double-bonded O will have 4 electrons (2 lone pairs).

### Step 3: Count the number of bonding pairs and lone pairs
- **Bonding pairs:** There are 3 bonding pairs (2 double bonds and 1 single bond).
- **Lone pairs:** There is 1 lone pair on the central Cl atom.

### Step 4: Calculate the steric number
- The steric number is the sum of the number of bonding pairs and lone pairs around the central atom.
- Steric number = Number of bonding pairs + Number of lone pairs = 3 (bonding) + 1 (lone) = 4.

### Step 5: Determine hybridization
- A steric number of 4 corresponds to \( \text{sp}^3 \) hybridization.

### Step 6: Determine the geometry and shape
- The geometry based on \( \text{sp}^3 \) hybridization is tetrahedral.
- However, since there is one lone pair, the shape of the molecule will be trigonal pyramidal.

### Conclusion
- The geometry of the \( \text{ClO}_3^{-} \) ion is tetrahedral, and its molecular shape is trigonal pyramidal.