Question

part 2 of 3
select the single best geometry of clo₃⁻ ion.
trigonal planar
bent
tetrahedral
trigonal pyramidal
part 3 of 3
enter the hybridization of the cl atom in the clo₃⁻ ion.

Explanation:

Step1: Calculate the number of valence - shell electron pairs around the central atom

The central atom in $ClO_{3}^{-}$ is $Cl$. Chlorine has 7 valence electrons, oxygen has 6 valence electrons and there is an extra electron due to the negative charge. The number of valence - shell electron pairs ($n$) around the central $Cl$ atom is calculated using the formula $n=\frac{7 + 3\times6+1}{2}=\frac{7 + 18 + 1}{2}=\frac{26}{2}=4$.

Step2: Determine the electron - pair geometry

With 4 electron - pair groups around the central atom, the electron - pair geometry is tetrahedral according to the VSEPR (Valence - Shell Electron - Pair Repulsion) theory.

Step3: Determine the molecular geometry

In $ClO_{3}^{-}$, there are 3 bonding pairs and 1 lone pair of electrons around the $Cl$ atom. According to VSEPR theory, when there are 3 bonding pairs and 1 lone pair, the molecular geometry is trigonal pyramidal.

Step4: Determine the hybridization

The number of hybrid orbitals is equal to the number of electron - pair groups around the central atom. Since there are 4 electron - pair groups around the $Cl$ atom in $ClO_{3}^{-}$, the hybridization of the $Cl$ atom is $sp^{3}$.

Answer:

Part 2 of 3: D. Trigonal pyramidal
Part 3 of 3: $sp^{3}$