Tin and its properties, tin ore

Tin is a substance, denoted by the symbol Sn and belonging to the group of light metals. At normal (room) temperature, does not react with either oxygen or water. Over time, it is able to be coated with a special film, which protects the metal from corrosion.

The density of tin is equal at an ambient temperature of 20 ° C of 7.3 grams per centimeter to a cubic centimeter, at a melting point (231.9 ° C) - 6.98 grams per centimeter cubic.

Tin exhibits the following oxidation states: +2, +4. The most common degree is +4, but tin with a degree of +2 is a strong reducing agent.

As already mentioned above, tin is resistant to the effects of oxygen and water at room temperature, but it can still be oxidized at temperatures above 150 ° C.

Heated tin reacts chemically with most non-metals, can react with sulfuric acid, but only if it is concentrated.

When carrying out the reaction between tin and concentrated nitric acid , the behavior characteristic of nonmetals is manifested, as a result of the reaction tin acid is formed.

It can react with diluted alkali in water, when heated, the tin hydroxide decomposes into oxide and water.

Unlike some other chemical elements, tin is obtained not as a result of reactions, but as a result of melting and purification of tin ore.

Tin ore is very important for humans, although relatively rare fossils. In Russia, the main deposit of this ore is located in Eastern Siberia, and tin in Yakutia can also be found.

The most common tin ore in the form of a tin stone, also called cassiterite. Presumably, the first cassiterites were found even in the time of Homer, and they were found in Greece - in fact the word cassiterite itself is of Greek origin.

Most likely, the tin stone was restored to tin completely by accident, and the beautiful metal is very fond of people. But it is quite obvious that it was very rare and expensive - among the surviving antiquities of Greece and Rome, objects from tin are found, but extremely rarely.

Currently, tin does not cost a lot of money, but even now the products from it are quite rare.

Deposits of tin stone are of two types: primary and secondary. In the first tin ore is included in granite and other rocks, and in the second is a small granule, mixed with clay.

To obtain a pure metal, tin ore melts in a special furnace for three days, after which the metal is drained. What is interesting, if slugs first enter the drain hole, then there will be little tin, and if the tin flows at once, leaving the slag behind, then its amount will be large enough.

Pure tin - beautiful, silver-white, soft metal - is used in many industries. From it, utensils, food tin, and containers for drinks are made. Also, this metal is a part of solders and additives, it is used to cover many metal products. Tin coating is done to protect the product from corrosion and improve its appearance.

In addition, tin easily forms various alloys with other metals, including bronze so well known to all. Moreover, tin, whose chemical properties are undoubtedly surprising, can form an alloy with carbon, in other words - an organometallic compound.

The role of organometallic (otherwise - organotin) compounds is very high: they are used in the manufacture of stabilizers for polyvinyl chloride, agricultural chemicals, wood paints.

In addition, some tin alloys are used to reduce the flammability and toxicity of many plastic and synthetic products produced during the combustion of smoke.