Question

The shape of a molecule of NH$_3$, in which the central atom contains a lone pair of electrons, is

• A. tetrahedral
• B. trigonal planar
• C. square planar
• D. pyramidal

Answer 1

The Correct Option is D

The VSEPR hypothesis, also known as the "Valence Shell Electron Pair Repulsion Theory," is based on the idea that all atoms have a repulsion between their pairs of valence electrons and that these atoms will always seek to organize themselves in a way that minimizes this repulsion. The shape of the final molecule is determined by this atom arrangement.

Around the core nitrogen atom of ammonia, there are 4 areas with high electron densities (3 bonds and 1 lone pair). They are positioned in a tetrahedral pattern. With H-N-H angles of 106.7°, the resultant molecular shape is trigonal pyramidal. The same structure is demonstrated as follows:

So, the structure looks like Trigonal Pyramidal.

• The gas ammonia has no color.
• Ammonia has a distinctive, powerful, pungent aroma that may be quite uncomfortable and constricting to the nose.
• Ammonia may be written as NH3, while nitrogen can be expressed as 1s² 2s² 2p³ in its electronic state. As a result, it is clear that nitrogen and hydrogen combine to create three bonds, leaving two lone pairs in their wake. Ammonia functions as a Lewis base as a result of these lone pairs.
• Ammonia, which is lighter than air, is very soluble in water.
• Artificial nitrogen fertilizers are created using ammonia.
• Under pressure, ammonia can liquefy. This liquid ammonia is subsequently employed as a refrigerant.
•  Ammonia is used to create colors, medicines, and cosmetics as well as fibers for the textile industry.
• Ammonia is a necessary solvent that is frequently employed in scientific settings.