Q. Choose the correct reaction to prepare mercurous chloride (calomel)
A) ${HgCl}_{2}\ + \ Hg\ \overset{\mathrm{\Delta}}{\rightarrow}$
B) $Hg\ + \ {Cl}_{2} \longrightarrow$
C) ${HgCl}_{2}\ + \ {SnCl}_{2} \longrightarrow$
D) Both (a) and (c)
Explanation
(d)
Mercurous chloride (calomel) is prepared by heating ${HgCl}_{2}$ and $Hg$ in iron vessel.
${HgCl}_{2} + Hg\ \overset{\mathrm{\Delta}}{\rightarrow}{Hg}_{2}{Cl}_{2}$
It can also be prepared by the reduction of mercury (II) chloride by tin (II) chloride in a limited quantity.
$2{HgCl}_{2} + {SnCl}_{2}\overset{\mathrm{\Delta}}{\rightarrow}{Hg}_{2}{Cl}_{2} + \ {SnCl}_{4}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.