The Question is from neet-chemistry , and it was created by the author CHANDRAKANTH

Question

Among the following statement, the correct statement about ${\rm{P}}{{\rm{H}}_3}$ and ${\rm{N}}{{\rm{H}}_3}$ is:

CHANDRAKANTH · Accepted Answer

## CORE INFORMATION
✓ **Answer**: C
## CONCEPT FRAMEWORK
	**Primary Concept**: Lewis base character and factors affecting it.
	**Related Topics**: Molecular geometry, orbital hybridization, electronegativity.
	**Prerequisites**: Basic understanding of Lewis acid/base concepts, orbital theory, and hybridization.
## SOLUTION PATHWAY
**Given Information**:
	Comparing the electron donating ability of NH3 and PH3
**Method & Steps**:
	1. Identify the relevant factor: The ability of a molecule to donate electrons (Lewis base character) is determined by the availability of its lone pair of electrons.
		Reasoning: A more accessible lone pair makes a molecule a better Lewis base.
		Formula/Rule: N/A
	2. Determine the orbital hybridization and geometry: In both NH3 and PH3, the central atom (N and P respectively) has a lone pair and three bonding pairs. This leads to sp3 hybridization and a pyramidal geometry.
		Working: N and P both have 5 valence electrons, they form 3 bonds and have a lone pair.
		Key Point: sp3 hybridization means the lone pair occupies an sp3 hybrid orbital.
	3. Evaluate the directionality of the lone pair: The lone pair in an sp3 hybrid orbital is directional, however, the size of the atom plays a key role. The smaller Nitrogen atom makes it more accessible compared to a larger Phosphorus atom.
		Result: NH3 is a better electron donor than PH3.
		Verification: The correct answer states that NH3 is a better electron donor due to its sp3 hybridized lone pair.
 ## OPTION ANALYSIS
[A] :x: Incorrect. The lone pair occupies an sp3 hybrid orbital, not a spherical s-orbital.
[B] :x: Incorrect. PH3 is not a better electron donor; its lone pair is not as accessible as NH3's.
[C] ✓: Correct. The lone pair in NH3 occupies a directional sp3 hybrid orbital, making it a better electron donor.
[D] :x: Incorrect. PH3 does not have a lone pair in a spherical s-orbital, and it is not a better electron donor.
 ## LEARNING AIDS
	**Common Mistakes**:
		1.Confusing s and sp3 orbitals: A common mistake is to assume that the lone pair resides in a spherical s-orbital. It's important to remember that hybridization occurs when atoms bond.
		2.Ignoring the effect of atomic size: The larger size of P makes its lone pair less accessible.
	**Quick Tips**:
		1.Remember that the availability of the lone pair directly affects the basicity of the molecule.
		2.Smaller central atoms tend to make better Lewis bases.

CHANDRAKANTH · Answer

${\rm{N}}{{\rm{H}}_3}$ is a better electron donor because the lone pair of electron occupies spherical s-orbital and is less directional

CHANDRAKANTH · Answer

${\rm{P}}{{\rm{H}}_3}$ is a better electron donor because the lone pair of electron occupies $s{p^3}$orbital and is more directional

CHANDRAKANTH · Answer

The correct Option is "${\rm{N}}{{\rm{H}}_3}$ is a better electron donor because the lone pair of electron occupies $s{p^3}$orbital and more directional"

CHANDRAKANTH · Answer

${\rm{P}}{{\rm{H}}_3}$ is a better electron donor because the lone pair of electron occupies spherical s-orbital and is less directional

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