Mercurous chloride exists in the form of

Mercurous chloride exists in the form of
  1. $\mathrm{Hg}^{+}$
  2. $\mathrm{Hg}_2^{2+}$
  3. $\mathrm{Hg}^{2+}$
  4. $\mathrm{Hg}_3{ }^{2+}$

Solution

Mercurous Chloride is a chemical compound with the formula \(\mathrm{Hg}_2 \mathrm{Cl}_2\). It is also known as mineral calomel or Mercurous chloride and is a rare mineral. It is a dense white or yellowish white and odourless solid. It is unique among the group 12 metals for its ability to form M-M. It is a linear molecule. Mercurous chloride is formed by the reaction of elemental mercury and mercuric chloride.
\(\mathrm{Hg}+\mathrm{HgCl}_2 \rightarrow \mathrm{Hg}_2 \mathrm{Cl}_2\)
It can be prepared by metathesis reaction involving aqueous mercury nitrate using various chloride sources including NaCl or HCl
\(2 \mathrm{HCl}+\mathrm{Hg}_2\left(\mathrm{NO}_3\right)_2 \rightarrow \mathrm{Hg}_2 \mathrm{Cl}_2+2 \mathrm{HNO}_3\)
Now, \(\mathrm{HgCl}_2\) can be broken down into \(\mathrm{Hg}^2\) ions and \(\mathrm{Cl}^{-}\)ions. The chemical reaction is as given below:
\(\mathrm{Hg}_2 \mathrm{Cl}_2 \rightarrow \mathrm{Hg}_2{ }^{2+}+2 \mathrm{Cl}^{-}\)
Therefore, the answer to our question is option B.

Asked in: NEET 2020 (Phase 1)

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