Solution:
HINT: $\text{XeF}_4$ and $\text{ICl}_4^-$ have identical shapes.
Explanation:
According to VSEPR Theory, the shape of a molecule depends on the number of bonding pairs and lone pairs of electrons around the central atom. Let's analyze each pair:
1. $\text{NO}_2^+$:
* Central atom: N
* Valence electrons on N = 5
* Bonding atoms (O) = 2. Each O forms a double bond, contributing 2 electrons to the bond. So, 2 $\sigma$ bonds.
* Charge: $+1$. So, 1 electron removed.
* Total valence electrons involved in bonding = $5 - 1 = 4$.
* Number of $\sigma$ bonds = 2. Number of lone pairs = $(4 - 2 \times 2)/2 = 0$.
* Hybridization = $\text{sp}$
* Shape = Linear
$\text{NO}_2^-$:
* Central atom: N
* Valence electrons on N = 5
* Bonding atoms (O) = 2. Each O forms a single bond, contributing 1 electron to the bond, with one O forming a double bond. Or more simply, count sigma bonds and lone pairs. $\text{NO}_2^-$ has 2 bonding pairs (2 $\sigma$ bonds) and 1 lone pair on the central Nitrogen atom.
* Hybridization = $\text{sp}^2$
* Shape = Bent or V-shaped (due to lone pair repulsion)
* Not identical shapes.
2. $\text{PCl}_5$:
* Central atom: P
* Valence electrons on P = 5
* Bonding atoms (Cl) = 5. All single bonds. So, 5 $\sigma$ bonds.
* Lone pairs = 0.
* Hybridization = $\text{sp}^3\text{d}$
* Shape = Trigonal bipyramidal
$\text{BrF}_5$:
* Central atom: Br
* Valence electrons on Br = 7
* Bonding atoms (F) = 5. All single bonds. So, 5 $\sigma$ bonds.
* Lone pairs = $(7 - 5)/2 = 1$.
* Hybridization = $\text{sp}^3\text{d}^2$
* Shape = Square pyramidal
* Not identical shapes.
3. $\text{XeF}_4$:
* Central atom: Xe
* Valence electrons on Xe = 8
* Bonding atoms (F) = 4. All single bonds. So, 4 $\sigma$ bonds.
* Lone pairs = $(8 - 4)/2 = 2$.
* Hybridization = $\text{sp}^3\text{d}^2$
* Shape = Square planar
$\text{ICl}_4^-$:
* Central atom: I
* Valence electrons on I = 7
* Bonding atoms (Cl) = 4. All single bonds. So, 4 $\sigma$ bonds.
* Charge: $-1$. So, 1 extra electron.
* Total electrons for lone pairs = $(7 + 1 - 4)/2 = 2$.
* Hybridization = $\text{sp}^3\text{d}^2$
* Shape = Square planar
* Identical shapes.
4. $\text{TeCl}_4$:
* Central atom: Te
* Valence electrons on Te = 6
* Bonding atoms (Cl) = 4. All single bonds. So, 4 $\sigma$ bonds.
* Lone pairs = $(6 - 4)/2 = 1$.
* Hybridization = $\text{sp}^3\text{d}$
* Shape = See-saw
$\text{XeO}_4$:
* Central atom: Xe
* Valence electrons on Xe = 8
* Bonding atoms (O) = 4. Each O forms a double bond, contributing 2 electrons to the bond. So, 4 $\sigma$ bonds.
* Lone pairs = 0 (all valence electrons used in double bonds).
* Hybridization = $\text{sp}^3$
* Shape = Tetrahedral
* Not identical shapes.
Thus, $\text{XeF}_4$ and $\text{ICl}_4^-$ have identical shapes (Square planar).