no secret that mercury compounds are highly toxic and toxic.In the US, it is prohibited for use in most of the cosmetic products and in Canada on the list of the most dangerous substances.However, they are widely used in the chemical industry for the manufacture of dyes, fungicides, plastics, as well as in medicine and engineering.One of the representatives of this class of substances is mercuric chloride (II), which is better known by his second name - sublimate.Let's look at this link in more detail.
formula and properties
mercury chloride 2-valent designated HgCl2.This compound is a white crystalline powder.At a temperature of 277˚ C it begins to melt, and when 304˚S - boil.Under normal conditions (25 ° C) has a density of 5.43 g / cm3.Mercuric chloride sublimates easily distinguished noticeable volatility.The solubility of mercuric chloride in water depends on its temperature.So, at 20 ° C the rate is only 6.6%, but it is necessary to bring water to a boil (100 ° C) and it reaches 58.3%.In addition, mercury chloride can dissolve in ether, acid, pyridine;NaCl solution in this process is accompanied by the formation of complex compounds.As the electrolyte HgCl2 is pretty weak.In daylight, especially when in contact with organic compounds, it is readily reduced to the monovalent chloride Hg2Cl2 (calomel) and metallic mercury.
Getting
in large quantities chloride, mercury (II) is now produced only by means of direct synthesis of mercury and chlorine.The second method is to obtain sublimate HgO dissolved in concentrated hydrochloric acid (HCl).In practice, it is rarely used, mainly - in the course of laboratory experiments.In the first case, the mercury is heated in an atmosphere of chlorine to a very high temperature (about 340˚S) then ignite and burn with the formation of a bluish-white flame.The vapors condense during cooling and, depending on the technology of obtaining, form a fine powder or solid pieces.
Application
worth noting that mercuric chloride was the first matter on the basis of Hg, which began to be used as an antiseptic and disinfectant.In this regard, mercuric chloride is highly efficient, but at the same time is very toxic.It is able to be absorbed through the skin and mucous membranes and accumulate in the human body.In the past, when people did not know about the danger posed by mercury chloride, was used to cure skin diseases.Now, in medicine it is used more for the disinfection of clothes, linen, health products, etc.Since this substance is very poisonous, its solutions are part of a special dye to inadvertently did not mixed with other medications.
In industry mercuric chloride is used in electroplating, wood preservation, with thermal metallization and bronzing.Zulema is used for the manufacture of batteries, paints for the underwater hulls of ships.Its use in tanning leather, lithography, photographs, as an insecticide etc.
