To determine which molecule or ion has a trigonal planar shape, let's first understand the characteristics of a trigonal planar geometry:
A trigonal planar shape occurs when a central atom is bonded to three other atoms and there are no lone pairs of electrons on the central atom. The bond angles between the atoms are approximately 120 degrees.
Now let's analyze each given molecule or ion:
A. [tex]\( SO_3 \)[/tex] (Sulfur Trioxide)
- The sulfur atom in [tex]\( SO_3 \)[/tex] is bonded to three oxygen atoms and there are no lone pairs on the sulfur atom. This fits the description of a trigonal planar geometry with bond angles of 120 degrees.
B. [tex]\( ClO^- \)[/tex] (Hypochlorite ion)
- The chlorine atom in [tex]\( ClO^- \)[/tex] is bonded to one oxygen atom and has three lone pairs of electrons. This does not form a trigonal planar shape.
C. [tex]\( H_2S \)[/tex] (Hydrogen Sulfide)
- The sulfur atom in [tex]\( H_2S \)[/tex] is bonded to two hydrogen atoms and has two lone pairs of electrons. This results in a bent shape rather than a trigonal planar shape.
D. [tex]\( PCl_5 \)[/tex] (Phosphorus Pentachloride)
- The phosphorus atom in [tex]\( PCl_5 \)[/tex] is bonded to five chlorine atoms. The geometry is trigonal bipyramidal, not trigonal planar.
Based on the descriptions, the molecule that has a trigonal planar shape is:
A. [tex]\( SO_3 \)[/tex]
So the correct answer is:
A. [tex]\( SO_3 \)[/tex]
