It is obtain by adding HCl to mercurous Nitrate solution.
Hg2 (NO3)2 +2HCl → Hg2Cl2 +2HNO3
It is obtained by heating mercuric chloride with Hg.
HgCl2+Hg → Hg2Cl2
Commercially it is obtained by heating HgSO4 and NaCl with Hg.
HgSO4 + Hg + NaCl → Hg2Cl2 + Na2SO4
It is white amorphous solid insoluble in water.
When heated strongly, it decomposes forming HgCl2 and Hg.
Hg2Cl2 → HgCl2 +Hg
Dissolves in aqueregia, forming mercuric chloride.
3HCl + HNO3 → NOCl + 2H2O +2Cl
Hg2Cl2 + 2Cl → 2HgCl2
Hg2Cl2 + 3Hcl +HNO3 → 2HgCl2 + NoCl + 2H2O
Action of NH3:
With NH3, Hg2 gives a black ppt of mercury and mercuric amino chloride,
Hg2Cl2 + NH3 → Hg + Hg (NH2) Cl + NH4Cl
- It is used medicine as mild purgative.
- It is used in making calomel electrode.