HgCl reacts with mercury in an iron vessel to form mercurous chloride. HgCl + Hg Hg Cl Δ -> 2. Mercurous chloride can also be prepared by the reduction of mercury chloride by tin. 2+ 2HgCl + SnCl Hg Cl SnCl ->

Mercurous chloride or 2 2 Hg Cl is known as the calomel. The reaction of calomel with ammonium hydroxide produces a black colour precipitate. This black ppt is a mixture of mercury metal and mercury (II) amido chloride 2 Hg(NH )(Cl) complex. The progress of the reaction is as follows, Thus, (d) is the correct option. 108. The following is known as “bordeaux mixture” (a) Borax and copper sulphate (b) Orthoboric acid and ferrous sulphate (c) Sodium borate and zinc sulphate (d) Copper sulphate and lime Bordreaux mixture is also known as the bordo mix. It is a mixtureof copper (II) sulphate 4 C