CramX Logo

Q
QuestionChemistry

Why is NH^3 classified as a polar molecule?
12 months agoReport content

Answer

Full Solution Locked

Sign in to view the complete step-by-step solution and unlock all study resources.

Step 1:
I'll solve this problem step by step, explaining why NH^3 (ammonia) is classified as a polar molecule:

Step 2:
: Understand Molecular Structure

Ammonia (NH3) has a trigonal pyramidal molecular geometry. The central nitrogen atom is bonded to three hydrogen atoms, with one lone pair of electrons on the nitrogen.

Step 3:
: Analyze Electronegativity

\text{Electronegativity difference} = 3.04 - 2.20 = 0.84
- Nitrogen has an electronegativity of 3.04 - Hydrogen has an electronegativity of 2.20

Step 4:
: Examine Bond Polarity

Nitrogen, being more electronegative, pulls the electron density towards itself, creating a partial negative charge ($$\delta^{-}$$) on nitrogen and partial positive charges ($$\delta^{+}$$) on the hydrogen atoms.
The difference in electronegativity creates polar N-H bonds.

Step 5:
: Consider Molecular Geometry

Due to the lone pair on nitrogen, the molecule is not symmetrically balanced. This asymmetry prevents the bond dipoles from canceling out.

Step 6:
: Determine Net Dipole Moment

The unequal distribution of charge creates a net dipole moment, with the negative charge concentrated toward the nitrogen atom.

Final Answer

1. It has polar N-H bonds 2. Its trigonal pyramidal geometry is asymmetric 3. The lone pair on nitrogen creates an uneven charge distribution 4. These factors result in a net dipole moment, making NH^3 a polar molecule.