Two different compounds have the formula \(\mathrm{XeF}_{2} \mathrm{Cl}_{2}\) . Write Lewis structures for these two compounds, and describe how measurement of dipole moments might be used to distinguish between them.

Firstly, we will create a possible Lewis structure of the first compound. Xe has a total of 8 valence electrons, F has 7, and Cl has 7. We can start by putting the Xe atom in the center and arranging the F and Cl atoms around it. In compound 1, let's consider that the two F atoms are positioned opposite to each other and the Cl atoms are also on opposite sides. The structure would look like: ``` F | Xe - Cl | F ``` Now, we will add lone pairs. Each F atom will have 3 lone pairs, and each Cl atom will have 2 lone pairs. The central Xe atom has no lone pairs left because it has 8 electrons and each bond contributes 2 electrons. The Lewis structure for compound 1 is: ``` :F: | :Cl-Xe-Cl: | :F: ```

For the second compound, let's consider that the F and Cl atoms are positioned adjacently. The structure would look like: ``` F | Cl - Xe - Cl | F ``` Adding the lone pairs like before, we have: ``` :F: | :Cl:Xe:Cl: | :F: ```

A dipole moment is a measure of the charge distribution in a molecule. It is described as the product of the charge and the distance between the atoms. The dipole moment (\(\mu\)) can be calculated using the formula: \[\mu = Q \times d\] Where: - \(Q\) denotes the charge difference between the bonded atoms. - \(d\) denotes the distance between the bonded atoms. Dipole moments are vector quantities. In a molecule, the overall dipole moment is determined by the vector sum of the individual bond dipole moments. A molecule with a net dipole moment is polar, whereas a molecule with no net dipole moment (the bond dipoles cancel each other out) is nonpolar.

In compound 1, the dipole moments of the opposite Xe-F and Xe-Cl bonds will cancel each other out, leading to an overall net dipole moment of zero. This compound is nonpolar. In compound 2, the bond dipole moments of the Xe-F and Xe-Cl bonds do not cancel each other out, leading to an overall non-zero net dipole moment. This compound is polar.

By measuring the dipole moments of the two compounds, we can distinguish between them. Since compound 1 has a net dipole moment of zero, it is nonpolar. On the other hand, compound 2 has a non-zero net dipole moment, making it a polar molecule. Using methods such as infrared or Raman spectroscopy, polar and nonpolar molecules can be distinguished based on their interactions with electromagnetic radiation. Therefore, by measuring the dipole moments and observing the behavior of the molecules in these techniques, it is possible to differentiate between compound 1 and compound 2.