Xenon tetrafluoride is prepared by heating Xe(g) and F_{2}(g ) at 400°C at high pressure in a nickel container. The equation is
Xe(g ) + 2\ F_{2}(g) → XeF_{4}(s)Predict the shape of a XeF_{4} molecule.
The Lewis formula for a XeF_{4}(s) molecule is
\begin{matrix} :\overset{..}{\underset{..}{F}} _{_{\diagdown }} \qquad _{_{\diagup }}\overset{..}{\underset{..}{F}}{} : \\ \overset{..}{\underset{..}{Xe}} \\ :\overset{..}{\underset{..}{F}}^{^{\diagup }} \qquad ^{^{\diagdown }}\overset{..}{\underset{..}{F}}: \end{matrix}This molecule belongs to the class AX_{4}E_{2}; so according to Figure 8.20c, we predict that XeF_{4}(s) is a square planar molecule. This shape is indeed that observed, as shown in Figure 8.22 (see also Interchapter K).