The hybridization of \(NCl_3\) and \(PCl_3\) are respectively:

Both \(sp^3\)

The correct answer is option 1. Both \(sp^3\).

Hybridization is a concept used to explain the bonding and geometry of molecules. It involves the mixing of atomic orbitals to form new, hybrid orbitals that are used for bonding. The type of hybridization depends on the number of electron pairs around the central atom.

Hybridization of \( \text{NCl}_3 \)

Electron Domain Count:

Central Atom: Nitrogen (N)

Bonding Pairs: Nitrogen forms three single bonds with three chlorine atoms.

Lone Pairs: Nitrogen has one lone pair of electrons.

Total Electron Domains: The total number of electron domains (bonding pairs + lone pairs) around the nitrogen atom is 4 (3 bonding pairs + 1 lone pair).

To accommodate four electron domains, nitrogen uses \( sp^3 \) hybridization.

Hybrid Orbitals: The \( sp^3 \) hybridization involves mixing one \( s \)-orbital and three \( p \)-orbitals to form four equivalent \( sp^3 \) hybrid orbitals.

Geometry: The electron domain geometry is tetrahedral, but the presence of one lone pair results in a trigonal pyramidal molecular geometry.

 In \( \text{NCl}_3 \), the nitrogen atom is surrounded by three chlorine atoms and one lone pair, resulting in a trigonal pyramidal shape.

Hybridization of \( \text{PCl}_3 \)

Electron Domain Count:

Central Atom: Phosphorus (P)

Bonding Pairs: Phosphorus forms three single bonds with three chlorine atoms.

Lone Pairs: Phosphorus has one lone pair of electrons.

Total Electron Domains: The total number of electron domains around the phosphorus atom is 4 (3 bonding pairs + 1 lone pair).

Similar to nitrogen, phosphorus also uses \( sp^3 \) hybridization to accommodate four electron domains.

Hybrid Orbitals: Phosphorus mixes one \( s \)-orbital and three \( p \)-orbitals to form four \( sp^3 \) hybrid orbitals.

Geometry: The electron domain geometry is tetrahedral, but the presence of one lone pair results in a trigonal pyramidal molecular geometry.

In \( \text{PCl}_3 \), the phosphorus atom is surrounded by three chlorine atoms and one lone pair, leading to a trigonal pyramidal shape.

Comparison

Both \( \text{NCl}_3 \) and \( \text{PCl}_3 \) have the same hybridization: \( sp^3 \).

Geometry: Both molecules exhibit a tetrahedral electron domain geometry due to the \( sp^3 \) hybridization, but due to the lone pair on the central atom, they both have a trigonal pyramidal molecular geometry.

Conclusion

Both nitrogen trichloride (\( \text{NCl}_3 \)) and phosphorus trichloride (\( \text{PCl}_3 \)) are \( sp^3 \) hybridized due to the presence of four electron pairs (three bonding pairs and one lone pair) around the central atom. Thus, the correct answer is: 1. Both \(sp^3\)