To determine which compound is isostructural with XeF\(_2\), we first need to understand the structure of XeF\(_2\). XeF\(_2\) has a linear geometry due to its electronic configuration and the concept of electron pair repulsion.
Let's explore the reasoning step-by-step:
Valence Shell Electron Pair Repulsion (VSEPR) Theory: This theory helps predict the shape of molecules based on electron pair repulsion. It considers both bonding and non-bonding electron pairs.
Structure of XeF\(_2\): Xenon (Xe) is a noble gas and typically has eight electrons in its valence shell. When it forms XeF\(_2\), it uses two electrons to form bonds with two fluorine atoms, and has three lone pairs remaining.
Using VSEPR theory:
Total electron groups = 5 (2 bonding pairs + 3 lone pairs).
This leads to a trigonal bipyramidal electron pair geometry, with the lone pairs occupying the equatorial positions to minimize repulsion. The result is a linear molecular shape for XeF\(_2\).
Analyzing ICl\(_2^-\): ICl\(_2^-\) has a similar consideration:
Iodine (I) has 7 valence electrons. In ICl\(_2^-\), iodine forms two bonds with chlorine atoms and has three lone pairs (since the negative charge adds one more electron).
Total electron groups = 5 (2 bonding pairs + 3 lone pairs), similar to XeF\(_2\).
Thus, ICl\(_2^-\) also forms a linear shape due to its trigonal bipyramidal electronic arrangement.
Conclusion: Both XeF\(_2\) and ICl\(_2^-\) are linear and have the same VSEPR geometry, making them isostructural.
Eliminating Other Options:
SbCl\(_3\) has a trigonal pyramidal shape due to three bonding pairs and one lone pair, incompatible with XeF\(_2\)’s linear structure.
BaCl\(_2\) has an ionic lattice structure, not molecular; thus, it cannot be isostructural with a covalent molecule like XeF\(_2\).
TeF\(_2\) does not have a linear structure; typically, it assumes a bent shape due to its lone pairs.
Therefore, the compound that is isostructural with XeF\(_2\) is ICl\(_2^-\).