substance potassium dichromate has several names, which, to a greater or lesser degree of frequency, are used depending on the field of use of the substance itself.Traditionally, chemical theory most commonly used names potassium dichromate or potassium bichromate potassium.When it comes to industrial use, then the connection is termed Chrompick.It is very important to understand exactly what kind of connection in question, because in everyday use Chrompick still called sodium dichromate to the formula Na2Cr2O7 * 2H2O.The chemical formula of potassium bichromate - K2Cr2O7.
physical properties of potassium bichromate following.Outwardly, this substance is an orange crystal, the crystal lattice of which is variable under the influence of temperature.When its value to 257 ° C triclinic lattice has the form of single crystals, and when the temperature rises above 257 ° C, it changes the view of the monoclinic.
potassium dichromate substance has a melting point of 396 ° C, with its increase over 500 ° C decomposes to K2CrO4 substance, Cr2O3 and oxygen.Specific gravity of potassium bichromate is 2.69 g / cm3.Potassium dichromate is highly soluble in aqueous solutions:
- at 0 ° C, 100 grams of water was completely dissolved 4.6 grams of potassium bichromate;
- at a temperature of 25 ° C, the same quantity of water can be completely dissolved already 15.1 grams, and when the temperature rises to 50 ° C - is 37.7 grams.
In alcohols, e.g., ethanol, slightly soluble potassium dichromate.
potassium dichromate forms a eutectic - composite slurry which crystallizes at the smallest temperature for this group of substances structurally compositional formula of which - H2O - Content bichromate K2Cr2O7 at 4.30% by weight.The melting point of this compound is only 0.63 ° C, and it boils at 104.8 ° C (content of potassium bichromate in solution - 52% by weight).
involving such substances as potassium dichromate, the reaction proceeds in the acidic environment if it is presented in aqueous solution.The substance is also a strong oxidizing agent, for example, by the reaction of sulfur and potassium bichromate salt obtained K2SO4 and chromium oxide.
The interaction of sulfuric and nitric acids, potassium dichromate polihromaty forms.When heating mixtures containing this compound and hydrogen peroxide are obtained easily exploding crystals peroxide, which, in turn, is an important component of explosives.
industrial production of potassium bichromate carried out through an exchange reaction Na2Cr2O7 with KCl, in which the solution is heated to enormous temperatures - around 1000 - 1300 ° C
used potassium dichromate, chemical properties of which are described above in the production of various dyes in textile and leatherindustry it is used in tanning leather.Distributed applications in woodworking and the manufacture of matches, the manufacture of pyrotechnic mixtures photos.If potassium Chrompick dissolved in sulfuric acid, a very effective solution for cleaning glass instruments in laboratories.As a component of the potassium potassium bichromate used in dry electrolytes, as well as in metallurgy as a rust inhibitor of metals and their alloys.
Chrompick potassium - an extremely toxic compound.Drops of its solution, falling on the exposed areas of the human body, destroy the skin.Even small concentrations of this substance can cause serious damage to the respiratory tract and damage the cartilage ligament tissue.There have been cases of kidney damage, liver and gastrointestinal tract.Therefore, the production of works with potassium dichromate should strictly implement precautions.Particular care should be taken to protect the respiratory system and skin.