Question

The tailing of mercury on exposure to air shows a change in oxidation state by one.

• A. True
• B. False

Answer 1

The correct option is A True

Tailing of mercury

• When Ozone $\left({\mathrm{O}}_3\right)$is passed through Mercury $\left(\mathrm{Hg}\right)$it loses its meniscus and it begins sticking to the glass wall due to the formation of the Mercurous oxide$\left({\mathrm{Hg}}_2\mathrm{O}\right)$.
• This phenomenon is known as the tailing of mercury.

The formation of Mercurous oxide

• $$\begin{gathered} 2\mathrm{Hg}\left(l\mathit{\right)}\mathit{}\mathit{}\mathit{}\mathit{}+{\mathrm{O}}_3\left(g\mathit{\right)}\mathit{}\mathit{}\mathit{}\mathit{}\to {\mathrm{Hg}}_2\mathrm{O}\left(l\right)+{\mathrm{O}}_2\left(g\right) \\ \left(\mathrm{Mercury}\right)\left(\mathrm{Ozone}\right)(\mathrm{Mercurous}(\mathrm{Oxygen}) \\ \mathrm{Oxide}) \end{gathered}$$
• Oxidation state of $\mathrm{Hg}$ is $0$.
• Oxidation state of $\mathrm{Hg}$ in ${\mathrm{Hg}}_2\mathrm{O}$ is$+1$.
• The Tailing of mercury indicates a change in the oxidation number of Mercury by one.
• Shaking the walls of glass with water retrieves the lost meniscus.

Therefore, The tailing of mercury on exposure to air shows a change in oxidation state by one is True.