Question

Among the following, which one is incorrect? \[ \text{BrF}_5 \rightarrow \text{Trigonal bipyramidal}, \quad \text{SF}_4 \rightarrow \text{See saw}, \quad \text{NH}_3 \rightarrow \text{Pyramidal}, \quad \text{XeF}_4 \rightarrow \text{Square planar} \]

• A. BrF$_5$ \quad Trigonal bipyramidal
• B. SF$_4$ \quad See saw
• C. NH$_3$ \quad Pyramidal
• D. XeF$_4$ \quad Square planar

Hint:

Use VSEPR theory to determine the molecular geometry of molecules based on the number of bonding pairs and lone pairs around the central atom.

Answer 1

The Correct Option is A

The question asks to identify the incorrect geometry among the listed molecules based on their electron geometry.

1. Step 1: Understand the molecular shapes. - BrF$_5$: The molecule has 5 fluorine atoms attached to a central bromine atom, with one lone pair of electrons on the bromine. According to the VSEPR theory, BrF$_5$ adopts an octahedral geometry, not trigonal bipyramidal. Therefore, the statement for BrF$_5$ is incorrect. - SF$_4$: This molecule adopts a see-saw geometry due to 4 bonding pairs and one lone pair of electrons on sulfur, which is correct. - NH$_3$: Ammonia adopts a pyramidal shape due to 3 bonding pairs and one lone pair of electrons on nitrogen, which is correct. - XeF$_4$: Xenon tetrafluoride has a square planar geometry because it has 4 bonding pairs and 2 lone pairs of electrons, making the geometry planar, which is correct. Thus, the incorrect geometry is for BrF$_5$, and the correct geometry is octahedral.