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 \( ClO_3^{-} \) ion according to the Valence Shell Electron Pair Repulsion (VSEPR) theory, we can follow these steps:

### Step 1: Count the Valence Electrons
First, we need to count the total number of valence electrons in the \( ClO_3^{-} \) ion.
- Chlorine (Cl) has 7 valence electrons.
- Each Oxygen (O) has 6 valence electrons, and there are three Oxygens, contributing \( 3 \times 6 = 18 \) electrons.
- The ion has an overall charge of -1, which means we add 1 more electron.

Total valence electrons = \( 7 + 18 + 1 = 26 \) electrons.

### Step 2: Determine the Lewis Structure
Next, we draw the Lewis structure for \( ClO_3^{-} \):
- Place Cl in the center and connect it to three O atoms with single bonds.
- Distribute the remaining electrons to satisfy the octet rule for the O atoms.
- After placing single bonds and completing the octets of the O atoms, we find that one of the O atoms will form a double bond with Cl to minimize the formal charges.

### Step 3: Identify Lone Pairs and Bonding Pairs
In the final Lewis structure:
- There are three Cl-O bonds (one double bond and two single bonds).
- There is one lone pair of electrons on the Cl atom.

### Step 4: Apply VSEPR Theory
According to VSEPR theory:
- Count the regions of electron density around the central atom (Cl).
- There are 3 bonding pairs (from the Cl-O bonds) and 1 lone pair.

This gives us a total of 4 regions of electron density.

### Step 5: Determine the Geometry
With 4 regions of electron density:
- The arrangement of 4 regions of electron density corresponds to a tetrahedral electron geometry.
- However, because one of these regions is a lone pair, the molecular geometry is trigonal pyramidal.

### Conclusion
Thus, the geometry of the \( ClO_3^{-} \) ion according to VSEPR theory is **trigonal pyramidal**.

### Final Answer
The geometry of \( ClO_3^{-} \) ion is **trigonal pyramidal**.

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