The expected number of ${}^{19}\mathrm{F}$ NMR spectral lines, including satellites, for $\mathrm{[XeF_5]^-}$ is [Abundance of ${}^{129}\mathrm{Xe}\,(\mathrm{I}=1/2)=26\%$ ]
(a)two
(b)twenty one
(c)three
(d)one
Answer
Answer (as printed): C
Explanation
$[\mathrm{XeF_5}]^{-}$: total electron domains $=7$, $sp^3d^3$ hybridization; Shape = Pentagonal Planar. As 74% Xe are NMR inactive, hence a singlet of five fluorine, and due to 26% (active) nuclei, a doublet of satellites. Hence, total number of signals is 3.