Question

which of the following molecules has a trigonal pyramidal molecular geometry? clf3 xef4 pcl3 bcl3 ch4

Explanation:

To determine molecular geometry, we use the VSEPR (Valence - Shell Electron - Pair Repulsion) theory. For a trigonal pyramidal geometry, the central atom has 4 electron - groups (3 bonding pairs and 1 lone pair).

• In $\text{ClF}_3$, the central Cl atom has 5 electron - groups (3 bonding pairs and 2 lone pairs), so its molecular geometry is T - shaped.
• In $\text{XeF}_4$, the central Xe atom has 6 electron - groups (4 bonding pairs and 2 lone pairs), and its molecular geometry is square planar.
• In $\text{PCl}_3$, the central P atom has 4 electron - groups (3 bonding pairs and 1 lone pair). According to VSEPR theory, it has a trigonal pyramidal molecular geometry.
• In $\text{BCl}_3$, the central B atom has 3 electron - groups (3 bonding pairs and 0 lone pairs), and its molecular geometry is trigonal planar.
• In $\text{CH}_4$, the central C atom has 4 electron - groups (4 bonding pairs and 0 lone pairs), and its molecular geometry is tetrahedral.

Answer:

C. $\text{PCl}_3$