Among the following compounds the one that is polar and has central atom with `sp^(3)` hybridisation is :

Options

A. `H_(2)CO_(3)`
B. `SiF_(4)`
C. `BF_(3)`
D. `HClO_(2)`

Answer

To determine which compound is polar and has a central atom with sp³ hybridization, we will analyze each compound step by step.

### Step 1: Identify the Compounds
We need to analyze the following compounds:
1. H₂CO₃ (Carbonic acid)
2. SiF₄ (Silicon tetrafluoride)
3. BF₃ (Boron trifluoride)
4. HClO₂ (Chlorous acid)

### Step 2: Determine Hybridization and Polarity

#### Compound 1: H₂CO₃
- **Valence Electrons**: Carbon (C) has 4, Oxygen (O) has 6 (3 O atoms = 18), and Hydrogen (H) has 1 (2 H atoms = 2). Total = 4 + 18 + 2 = 24 valence electrons.
- **Bonding**: C forms 1 double bond with O and 2 single bonds with OH groups.
- **Lone Pairs**: No lone pairs on C.
- **Steric Number**: 3 (1 double bond counts as 1, and 2 single bonds).
- **Hybridization**: sp² (not sp³).
- **Shape**: Trigonal planar.
- **Polarity**: The molecule is polar due to the presence of the OH groups and the asymmetrical shape.

#### Compound 2: SiF₄
- **Valence Electrons**: Silicon (Si) has 4, Fluorine (F) has 7 (4 F atoms = 28). Total = 4 + 28 = 32 valence electrons.
- **Bonding**: Si forms 4 single bonds with F.
- **Lone Pairs**: No lone pairs on Si.
- **Steric Number**: 4.
- **Hybridization**: sp³.
- **Shape**: Tetrahedral.
- **Polarity**: The molecule is non-polar because the dipole moments of the Si-F bonds cancel out due to symmetry.

#### Compound 3: BF₃
- **Valence Electrons**: Boron (B) has 3, Fluorine (F) has 7 (3 F atoms = 21). Total = 3 + 21 = 24 valence electrons.
- **Bonding**: B forms 3 single bonds with F.
- **Lone Pairs**: No lone pairs on B.
- **Steric Number**: 3.
- **Hybridization**: sp² (not sp³).
- **Shape**: Trigonal planar.
- **Polarity**: The molecule is non-polar due to symmetry.

#### Compound 4: HClO₂
- **Valence Electrons**: Chlorine (Cl) has 7, Oxygen (O) has 6 (2 O atoms = 12), and Hydrogen (H) has 1 (1 H atom = 1). Total = 7 + 12 + 1 = 20 valence electrons.
- **Bonding**: Cl forms 1 double bond with O and 1 single bond with OH.
- **Lone Pairs**: Cl has 2 lone pairs.
- **Steric Number**: 4 (1 double bond + 1 single bond + 2 lone pairs).
- **Hybridization**: sp³.
- **Shape**: Bent (due to lone pairs).
- **Polarity**: The molecule is polar because the dipole moments do not cancel out due to the bent shape.

### Conclusion
The compound that is polar and has a central atom with sp³ hybridization is **HClO₂**.

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