Iron (III) chloride in the form of brown color solution may be prepared in the laboratory or at home.It takes the heat-resistant non-metallic utensils and clean hot water (bottled or distilled).After dissolution and sedimentation turns dark brown liquid.There are a number of features of a solution of ferric chloride, which should know before you start working with him.
Ferric Chloride
anhydrous ferric chloride, manufactured by the chemical industry - FeCl3, - crystals of dark brown color with shades of red, purple, dark green.Molar mass - 162.21 g / mol.The substance melts at a temperature of 307,5 ° C, at 500 ° C begins to decompose.In 100 g of water dissolved weighed anhydrous salt:
- 74,4 g (0 ° C);
- 99 g (25 ° C);
- 315 g (50 ° C);
- 536 g (100 ° C).
anhydrous ferric chloride (III) - a very hygroscopic substance quickly draws moisture from the environment.In the air reacts with water, turning into yellow crystals hexahydrate FeCl3 + 6H2O.Mass fraction of anhydrous ferric chloride in the material acquired in the trading network, reaching 95%.There is a small amount of ferric chloride FeCl2 and insoluble impurities.The trade name - "Ferric Chloride."Substance fire and explosion, but its solution has a corrosive effect on metal objects.
chloride hexahydrate Iron (III)
addition of anhydrous crystalline industry produces, it mass fraction of chloride iron (III) is 60%.The substance is a yellow-brown crystalline mass or loose pieces of the same color.An important feature of the ions and ferric iron - color.For the degree of oxidation of Fe2 + typical greenish, hydrated ferric chloride hexahydrate - bluish-green substance.The oxidation state Fe3 + ions acquire the color from yellow to brown.For the qualitative determination on a solution of ferric chloride reagents are:
- NaOH (appears brown precipitate Fe (OH) 3);
- K4 [Fe (CN) 6] (precipitate appeared KFe [Fe (CN) 6], blue);
- KCNS, NaCNS (formed thiocyanate iron Fe (CNS) 3 red).As
dilute ferric
Iron (III) chloride solution as a brown or red color can be found in commerce, prepared in the laboratory or at home.In the latter case necessarily require heat-resistant non-metallic containers (glass, plastic, ceramic).The water to dissolve the salt can be taken from the tap.Safety - boiled or distilled.Heat to 50-70 ° C water was placed in a container and then poured in small portions substance.The proportions of ferric chloride and water - 1: 3.If you prepare a solution of crystalline, it will require less water, because it is contained in crystal (40% by weight).Add the substance in the solution gradually, each serving - about 5-10 g Immediately pour the entire hitch is not recommended due to the rapid nature of the hydration reaction.Do not use metal utensils (spoons, spatulas).The salt should be completely dissolved in the warm water, the crystals need to mix well with the liquid.It accelerates the process of adding hydrochloric acid (1/10 by weight of the crystals).After standing for several hours at the bottom of the precipitate may occur due to the presence in the test portion and formation during the reaction of the iron hydroxide.It filtered dilution of dark brown color and store in a tightly sealed plastic container at a moderate temperature and the absence of direct sunlight.
The use of ferric chloride in industry and utilities.Domestic use
Iron salts are used in many fields.Trivalent metal chloride used for water treatment and metal fastening paints.The substance used in industrial organic synthesis (catalyst, oxidant).Especially prized coagulating properties of Fe3 + ion in the treatment of municipal and industrial wastewater.Under the action of the ferric chloride minor impurities insoluble particles coalesce and precipitate.Also, the binding of the soluble contaminants are removed in sewage treatment plants.The crystalline and anhydrous salt FeCl3 etching processes are used in the metal plates.Add the substance into the concrete to reinforce its strength.
chemical phenomena at etching circuit boards.Safety
Popular chemical etching circuit boards - ferric chloride.A solution for this purpose is prepared from 0.150 kg of salt and 0.200 liter of warm water.It contains the ions Fe3 +, Cl-, and the compound formed by hydrolysis brown - ferric hydroxide.The process follows the scheme: FeCl3 + 3HOH↔ Fe (OH) 3 + 3Cl- + 3H +.The disadvantage is the pollution board reaction byproducts that make it difficult to further etching.The very salt - a fatty substance, but in the process of interaction with water, emits corrosive fumes.The work should be carried out outdoors or in a well-ventilated room.Contact with skin and mucous membranes leads to irritation and may cause dermatitis.Use personal protective equipment (goggles, gloves).In contact with the caustic solution is necessary to wash the skin with plenty of water.
