Class 12 NEET Chemistry D And F Block Elements Questions

Concept: Reaction of calomel ($\mathrm{Hg}_2\mathrm{Cl}_2$) with aqueous ammonia ($\mathrm{NH}_4\mathrm{OH}$) leads to a disproportionation reaction.Explanation:When calomel ($\mathrm{Hg}_2\mathrm{Cl}_2$) is treated with ammonium hydroxide ($\mathrm{NH}_4\mathrm{OH}$), it undergoes disproportionation to give a black mixture of elemental mercury ($\mathrm{Hg}$) and a white precipitate of mercury(II) amido chloride ($\mathrm{HgNH}_2\mathrm{Cl}$).The balanced chemical equation for this reaction is:$$\mathrm{Hg}_2\mathrm{Cl}_2 + 2\mathrm{NH}_4\mathrm{OH} \rightarrow \mathrm{Hg} + \mathrm{HgNH}_2\mathrm{Cl} + \mathrm{NH}_4\mathrm{Cl} + 2\mathrm{H}_2\mathrm{O}$$Therefore, one of the main products obtained is $\mathrm{HgNH}_2\mathrm{Cl}$.Answer: Option C