A Chlorine gas $\left(\mathrm{Cl}_{2}\right)$ is used as a disinfectant in municipal water supplies, although chlorine dioxide $\left(\mathrm{ClO}_{2}\right)$ and
ozone are becoming more widely used. $\mathrm{ClO}_{2}$ is a better
choice than $\mathrm{Cl}_{2}$ in this application because it leads to fewer chlorinated byproducts, which are themselves polTutants.
(a) How many valence electrons are in $\mathrm{ClO}_{2} ?$
(b) The chlorite ion, $\mathrm{ClO}_{2}^{-}$, is obtained by reducing $\mathrm{ClO}_{2} .$ Draw a possible electron dot structure for $\mathrm{ClO}_{2}^{-},(\mathrm{Cl} \text { is the central atom. })$
(c) What is the hybridization of the central Cl atom in $\mathrm{ClO}_{2}^{-} ?$ What is the shape of the ion?
(d) Which species has the larger bond angle, $\mathrm{O}_{3}$ or $\mathrm{ClO}_{2}^{-} ?$ Explain bricfly.
(e) Chlorine dioxide, $\mathrm{ClO}_{2},$ a yellow-green gas, can be made by the reaction of chlorine with sodium chlorite: