Tin chloride is a reagent with a wide range of applications

Tin(II) chloride, or stannous chloride

SnCl2•2H2O is obtained by dissolving tin in hydrochloric acid and forms colorless crystals with two molecules of water of crystallization. When heating or strongly diluting a SnCl2 solution with water, partial hydrolysis occurs with the formation of a precipitate of the main salt:

SnCl2 + H2O ⇄ ↓SnOHCl + HCl

Stannous chloride is an energetic reducing agent.

So, for example, ferric chloride FeCl3 is reduced by it into ferric chloride FeCl2:

2FeCl3+ SnCl2 = 2FeCl2 + SnCl4

When tin chloride acts on a solution of sublimate, a white precipitate of calomel is formed. With an excess of SnCl2, the reduction goes even further and metallic mercury is obtained:

2HgCl2 + SnCl2 = ↓ Hg2Cl2 + SnCl4

Hg2Cl2 + SnCl2 = 2Hg + SnCl4

Tetravalent tin compounds. Tin dioxide

SnO2 occurs naturally in the form of tinstone, the most important ore of tin. It can be produced artificially by burning the metal in air or by oxidizing it with nitric acid, followed by calcination of the resulting product. Used for preparing various white glazes and enamels.

How to make tin at home? Step by step casting process

The melting point of tin is only 231 °C. But its boiling point is within 2,300 °C. The temperature at which the metal will be melted can be achieved at home.

That is, it is quite possible, of course, subject to certain rules and safety precautions, to perform tin casting at home. In industrial conditions, special centrifugal casting machines are used for tin casting.

To make molds, gypsum, alabaster, epoxy resin, silicone and, of course, metal are used.

Tin casting process in industry

Creating a form is perhaps the most important process. First you need to create a sketch of the future model. After this, the model is made from polymer clay. To apply small parts you must use an awl.

Another, no less important process is the production of injection molds. When manufacturing it, it is necessary to ensure that the correct connector is present.

It is needed so that the finished casting can be removed without causing damage to the product itself.

Silicone tooling for tin casting

Making equipment from silicone will require more material and time. This is because it must be subjected to a vulcanization process.

But as a result of all the hassle, multi-turn equipment for casting tin products will be obtained. If the future part is quite complex, then it will be necessary to provide for the presence of embedded parts.

We must not forget about the air ducts; air must escape through them as the mold is filled with tin.

An important element of the design of the equipment is the hole through which the filling will be performed. If it is small, the metal will flow too slowly and the solidification process may begin before it is completely filled.

Before casting begins, the mold halves must be joined together and placed between a sheet of plywood. The sheet must be at least 12 millimeters thick, and the size must exceed the dimensions of the metal mold.

Upon completion of assembly, the entire structure is tied together with a rope.

Two half-forms between sheets of plywood, tied together with a rope

Casting technology is not very complicated; it makes sense to prepare the metal for pouring after the final assembly of the mold. To do this, it needs to be warmed up well. Once a yellowish film appears on its surface, we can assume that the tin is ready for pouring.

If the metal is overheated, a blue or purple film will float on the surface of the melt. Molten metal is poured in a thin stream. In this case, you can lightly tap the housing to remove air. You can open the mold only after the cast part has completely cooled. To remove the casting, you need to use forceps.

You must be prepared for the fact that the first product received will have some surface defects.

Removing excess tin (burr)

The machining sequence is as follows. First, the flash is removed. So, they call the excess melt that flows into the seam of the mold. A scraper is used for this. Side cutters are used to remove the sprues. For final processing of seams, use abrasive sandpaper with the finest grain (zero).

Everything you need to know about liquid tin, making your own solution

Tin is one of the chemical elements that has found application in various industrial areas and everyday life. It is a light metal, ductile, malleable and fusible. It has a silvery-white tint and shine. One form of the substance is liquid.

Mainly used in radio construction. Liquid tin is ideal for chemical tinning of copper parts, in particular printed circuit boards.

This treatment method significantly increases their service life and prevents the formation of corrosion.

Tools and materials for casting

Tin is almost an ideal material for casting in both domestic and industrial settings. What materials and tools will be needed to produce the mold and perform casting. To make the mold you will need sealant and plaster. The first will be used to make the equipment itself, and gypsum will be needed to make the frame into which the technological equipment will be installed.

Tin Casting Tools

In addition to the materials mentioned above, you will need simple metalworking tools - files with different sections, pliers, a soldering iron, etc.

How to make soldiers with your own hands from different materials

• July 4, 2019
• Crafts
• Natalia Penchkovskaya

Soldiers for boys' games can be made from absolutely different materials - from wood and ice cream sticks, from paper and cardboard, cut out of wood or poured into a mold using tin. In this article we will look at how to make soldiers with your own hands. These are simple options that even schoolchildren can handle making.

You'll learn how to quickly create an army out of cardboard toilet paper rolls and paper straws. We will also consider ways to sculpt soldiers from plasticine or clay, and also tell you how to properly pour tin warriors in self-prepared plaster molds.

To make uniforms for a man with a weapon or simply in military uniform, a variety of materials are used. Then the blank needs to be painted in the chosen colors, be it a modern warrior or a soldier of an ancient army. A child can show his imagination and decorate his uniform with any small details.

Depending on the type of base material, gouache or acrylic paints are chosen; tin men can simply be sanded and rubbed with felt so that the soldier shines like a mirror.

Tin casting molds

For the manufacture of injection molding equipment, materials such as gypsum or silicone are used. It all depends on the part and its purpose. The simplest one is gypsum. To make it you will need a wooden box, some plaster and a piece of metal tube.

Creating a snap-in is performed in several steps:

1. Preparation of gypsum mixture. It should resemble thick sour cream in appearance.
2. The mixture is poured into a pre-prepared box and leveled.
3. To obtain a half-mold, you need to take the part and immerse it halfway in the prepared plaster. A similar operation must be performed with the second half of the part. As a result, 2 half-forms will be obtained.
4. The halves must be connected, or fastened with locks, or simply tied together with a tight elastic band. A prepared metal pipe must be inserted into the place through which the molten tin will be poured.

In principle, the injection molding equipment is ready for use. The molten tin can be safely poured into the resulting mold.

What is the difference between gypsum forms and others - the main thing is that they have less durability. If their surface is not prepared, then such equipment can withstand one or two cycles.

Tin products and other applications of pure metal, as well as its various alloys

Despite its name - “resistant”, tin is not a durable metal. It is too light and malleable to be used for the production of any load-bearing structures.

But malleability at relatively low temperatures and plasticity make the substance very popular in the relevant field.

You will learn all this and even more from this article about how you can use tin, where to buy it for soldering, what solders are possible with it.

Stannic acids

Tin dioxide hydrates are called stannous acids and are known in two modifications: as α-stannous acid and as β-stannic acid. α -Stannic acid

H2SnO3 can be prepared by reacting an aqueous ammonia solution with a solution of tin chloride SnCl4.

The formation of the white precipitate that falls is usually expressed by the equation

SnCl4+

4NH4OH = ↓ H2SnO3 + 4NH4Cl + H2O

As the precipitate dries, it gradually loses water until pure tin dioxide remains. Thus, no acid of a specific composition can be obtained. Therefore, the above formula for α-stannous acid is only the simplest possible. It would be more correct to depict the composition of this acid with the formula mSno2 • nH2O.

α-Stannic acid easily dissolves in alkalis, forming salts containing the complex anion [Sn(OH)6] - and called stannates:

H2SnO3 + 2NaOH + H2O = Na2[Sn(OH)6]

Sodium stannate is released from solution in the form of crystals, the composition of which can also be expressed by the formula Na2SnO3 • 3H2O. This salt is used as a mordant in dyeing and to weigh down silk. Silk fabrics treated with solutions of tin compounds before dyeing sometimes contain tin in amounts up to 50% by weight of the fabric.

Acids also dissolve α-stannous acid to form stannous salts. For example:

H2SnO3 + 4HCl ⇄ SnCl4 + 3H2O

When there is an excess of hydrochloric acid, SnCl4 adds two HCl molecules, forming complex chlorotin acid H2[SnCl6]. The ammonium salt of this acid, NH4[SnCl6], has the same uses as sodium stannate.

Links[edit]

1. ^ abc Egon Wiberg, Arnold Frederick Holleman (2001). Inorganic chemistry
   . Elsevier. ISBN 0-12-352651-5.
2. Reiter, Hans; Pawlak, Rüdiger (April 2000). "Die Molekül- und Kristallstruktur von Zinn (IV) -chlorid". Zeitschrift für anorganische und allgemeine Chemie
   (in German).
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   (4):925–929. DOI: 10.1002 / (SICI) 1521-3749 (200004) 626: 4 <925:: AID-ZAAC925> 3.0.CO; 2-R.
3. Barnes, John S.; Sampson, Hazel A.; Weekley, Timothy Jr. (1980). “Structures of di-μ-hydroxobis [aquatrichlorotene (IV)] - 1,4-dioxane (1/3), di-μ-hydroxobis [aquatrichlorotene (IV)] - 1,8-epoxy-p-menthane (1/4 ), di-m-hydroxobis [aquatribromotin (IV)] - 1,8-epoxy-p-menthane (1/4), di-μ-hydroxobis [aquatrichlorotene (IV)] and cis-diaquatetrachlorotene (IV) ". J. Chem.
   Soc., Dalton Trans. (6): 949. DOI: 10.1039/DT9800000949.
4. Genge, Anthony RJ; Levason, William; Patel, Rina; Reid, Gillian; Webster, Michael (2004). "Tan tetrachloride hydrates". Acta Crystallographica Section
   C.
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   (4): i47–i49. DOI: 10.1107/S0108270104005633. PMID 15071197.
5. Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of elements
   (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
6. Thurston, David E.; Murthy, Varanasi S.; Langley, David R.; Jones, Gary B. (1990). " O-
   Debenzylation of pyrrolo[2,1-
   c
   ][1,4]benzodiazepine in the presence of a carbinolamine functional group: synthesis of DC-81".
   Synthesis
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7. ↑
   G. G. Graf "Tin, Tin Alloys and Tin Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2005 Wiley-VCH, Weinheim. DOI: 10.1002/14356007.a27_049
8. Jump up
   ↑ Fries, Amos A. (2008).
   Chemical warfare
   . Read. pp. 148–49, 407. ISBN 978-1-4437-3840-8..

β-Stannic acid

It is obtained in the form of a white powder by the action of concentrated nitric acid on tin. Its composition is as uncertain as the composition of α-stannous acid. Unlike α-stannous acid, it does not dissolve in either acids or alkali solutions. But by fusing with alkalis it can be transferred into solution in the form of a stannate. When α-stannous acid is stored in contact with the solution from which it was isolated, it gradually also transforms into β-stannous acid.

Tin chloride

(IV), or
tin chloride,
SnCl4 is a liquid that boils at 114° and smokes strongly in air. Formed by the action of chlorine on metal tin or tin dichloride. In technology it is obtained mainly by treating waste tinplate (old tin cans) with chlorine.

Although tin chloride is similar in some properties to chloride compounds of metalloids, it dissolves in water without noticeable decomposition and can be isolated from solution in the form of various crystalline hydrates, for example SnCl4 • 5H2O.

In dilute aqueous solutions, SnCl4 undergoes strong hydrolytic degradation, which can be expressed by the equation

Sn•••• + 3H2O ⇄ H2SnO3 + 4H•

The resulting tin acid gives a colloidal solution.

Application

• In the chemical industry - a reducing agent in organic syntheses, a raw material for the production of tin, a catalyst for the polymerization of materials based on epoxy resins. It is in demand in metal reduction reactions and for the clarification of mineral oils obtained from petroleum. • Reagent for the detection of iodine, chlorine, divalent mercury, ferric iron and some others ions in solution in laboratory practice. • In the cosmetics industry to obtain flavors and dyes for soap. • To obtain mordants for dyeing fabrics. • In the production of ceramics. • For the manufacture of highly reflective products, mirrors. For polishing glass and plastic surfaces to give them better adhesion to the next reflective metal coating. For chemical tinning (coating surfaces with a layer of tin). • Food additive E512 in the food industry - emulsifier, shape and consistency stabilizer. Used to whiten sugar. • Included in the flux for welding. • Used to test gold bars if they are suspected of being counterfeit.

Tin sulfides

The action of hydrogen sulfide on a SnCl2 solution produces a brown precipitate of tin sulfide

(II) SnS.
of tin disulfide
precipitates from the SnCl4 solution under the same conditions . The latter compound can also be obtained dryly, for example by heating tin filings with sulfur and ammonia. The disulfide prepared using this method has the appearance of golden-yellow flakes and is called “gold leaf” and is used for gilding wood.

Tin disulfide dissolves in sulfur alkalis and in a solution of ammonium sulfide, and easily soluble salts of thiotin acid

H2SnS3:

SnS2 + (NH4)2S = (NH4)2SnS3

Free thiotinic acid (like the corresponding arsenic and antimony thioacids) is not known. When acids act on its salts, hydrogen sulfide is released and tin disulfide is again obtained:

(NH4)2SnS3 + 2HCl = ↓SnS2 + H2S + 2NH4Cl

Tin (II) sulfide does not dissolve in sulfur alkalis, since there are no thiosalts corresponding to divalent tin. But polysulfur alkalis dissolve it to form salts of thiotin acid:

SnS + (NH4)2S. = (NH4)aSnSs

Tin hydrogen

SnH4 was first obtained in 1919 as an admixture to hydrogen by the action of hydrochloric acid on an alloy of magnesium and tin. This is a colorless, very poisonous gas that condenses into liquid at -52° and gradually decomposes at ordinary temperatures into tin and hydrogen.

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Precautionary measures

Tin dichloride and its crystalline hydrate are considered non-toxic, but dust can cause irritation to the skin and mucous membranes. Dangerous in case of contact with eyes or if swallowed.

When working with the reagent, enterprises should use protective clothing, gloves, masks and goggles.

Store the substance in dry rooms with temperature control and a ventilation system, away from strong oxidizing agents. The packaging must be sealed to prevent exposure to oxygen and moisture in the air.

DIY liquid tin

Tin is one of the chemical elements that has found application in various industrial areas and everyday life. It is a light metal, ductile, malleable and fusible. It has a silvery-white tint and shine. One form of the substance is liquid.

Mainly used in radio construction. Liquid tin is ideal for chemical tinning of copper parts, in particular printed circuit boards.

This treatment method significantly increases their service life and prevents the formation of corrosion.

The Tale of the Alloy Rose and the Fallen Krenka

A long, long time ago, when I was a schoolboy and was extracting radio components mainly from various boards thrown into a landfill, I noticed an unusual phenomenon in the process of soldering another such board: some solders instantly fell off the foil as soon as I poked them with a soldering iron. The pad remained clear of solder, smooth and silver-tinted, and the drop of solder on the part's lead had the same shiny, flat base at the bottom. I noticed and forgot for the time being.

And the year before last, while taking part in a scientific expedition to the Arctic, I unexpectedly encountered an unexpected failure of the device I was working with.

The device was homemade - other people made it, but fortunately, they provided me with a circuit diagram and all the documentation; I took a soldering iron and the necessary equipment with me, just in case.

It didn’t take long to find the fault: inside the case there was an integrated 5 V stabilizer in a D-Pak case, which simply fell off the board.

Specification

Chemical structure

SnCl 2 has a lone pair of electrons, so the molecule in the gas phase is bent. In the solid state, crystalline SnCl 2 forms chains linked by chloride bridges as shown. The dihydrate is also three-coordinated: one water coordinates with tin, and a second water coordinates with the first. The main part of the molecule fits into double layers in a crystal lattice, and the “second” water is sandwiched between the layers.

Structures of tin(II) chloride and related compounds Ball-and-stick models of the crystal structure of SnCl 2 [3]