Question

According to VSEPR theory, the set(s) of species having trigonal bipyramidal geometry is(are)

• A. PCl\(_5\) and SF\(_4\)
• B. ClF\(_3\) and I\(^-\)
• C. PCl\(_5\) and Sb(Ph)\(_5\)
• D. ClF\(_3\) and BrF\(_5\)

Hint:

Trigonal bipyramidal geometry occurs when there are 5 bonding pairs of electrons around the central atom with no lone pairs, or when there is 1 lone pair in the case of a see-saw structure.

Answer 1

The Correct Option is A

Step 1: VSEPR theory.
VSEPR (Valence Shell Electron Pair Repulsion) theory helps in determining the molecular geometry by considering the repulsion between electron pairs around the central atom.
Step 2: Geometries of the species.
- PCl\(_5\) has 5 bonds and 0 lone pairs on the central phosphorus atom, leading to a trigonal bipyramidal geometry.
- SF\(_4\) has 4 bonds and 1 lone pair, giving it a trigonal bipyramidal geometry with a see-saw shape.
- ClF\(_3\) has 3 bonds and 2 lone pairs on the central chlorine atom, resulting in a T-shaped geometry, not trigonal bipyramidal.
- I\(^-\) is a single atom and cannot have a trigonal bipyramidal geometry.
- Sb(Ph)\(_5\) has 5 bonds and no lone pairs on the central antimony atom, which gives a trigonal bipyramidal geometry.
- BrF\(_5\) has 5 bonds and 0 lone pairs on the central bromine atom, which also has a square pyramidal geometry, not trigonal bipyramidal.
Step 3: Conclusion.
The correct species with trigonal bipyramidal geometry are PCl\(_5\) and SF\(_4\), so option (A) is correct.
Final Answer: \[ \boxed{\text{PCl}_5 \text{ and SF}_4} \]