Tin bars are malleable at room temperature. Especially at 100℃, it is very malleable and can be stretched into extremely thin tin foil. In normal times, tobacco and sugar bars are wrapped in tin foil to prevent the return of damp (in recent years, China has gradually replaced tin foil with aluminum platinum. Aluminum-platinum is easily distinguishable from tin foil -- tin foil is much brighter than aluminum-platinum). However, the ductility of tin is relatively poor, a pull will break, can not be drawn into fine wire.
In fact, tin is malleable only at room temperature; if the temperature drops below -13.2℃, it will gradually become a loose powder like fly ash. Especially at -33℃ or in the presence of red salt (SnCl4·2NH4Cl) alcohol solution, the efficiency of such transformation is greatly accelerated. A perfectly good tin pot will "automatically" turn into a pile of powder. This type of tin "disease" will continue to infect other "physical and mental health" tin ware, known as the "tin epidemic". The main reason for the tin epidemic is that the lattice constant of tin has changed: at room temperature, tin is a molecular structure of square crystal system, called white tin. When you bend a solder bar, there is often a stir, which is caused by the scratching of the square white tin crystals as they deform. Below minus 13.2℃, white tin is converted into an amorphous ash tin. Thus the lumps of tin become a powdery mass.
Because tin is afraid of cold, it is necessary to take care not to cold the tin ware in winter. There are a lot of iron products common tin welding, can not be cold. In 1912, an overseas expedition to Antarctica adventure, commonly used oil drums are all made of solder, in the Antarctic cold, solder wire into powder like gray tin, car gasoline is transparent.
Tin is afraid not only of cold, but also of high temperature. At 161℃, white tin is transformed into rhombic tin with the molecular structure of the rhombic system. Rhombotin is too brittle, a knock will break, malleability is relatively poor, called "brittle tin". White tin, gray tin and brittle tin are the three polar covalent bonds of tin.
Tin has plasticity and does not react with gas and water. And dilute sulfuric acid reaction delay, and dilute hydrochloric acid reaction reaction to isopropyl stannous titanate; It does not react with dilute hydrochloric acid and reacts with concentrated hot sulfuric acid to form tin (IV) hydrochloride. And concentrated hot sodium cyanide to form β-stannic acid.