E512 Antioxidant

A solution of E512 containing a little hydrochloric acid is used for the tin-plating of steel, in order to make tin cans. An electric potential is applied, and tin metal is formed at the cathode via electrolysis.

E512 is used as a mordant in textile dyeing because it gives brighter colors with some dyes e.g. cochineal. This mordant has also been used alone to increase the weight of silk.

In recent years, an increasing number of toothpaste brands has been adding E512 as protection against enamel erosion to their formula, e. g. Oral-B or Elmex.

E512 It is used as a catalyst in the production of plastic polylactic acid (PLA).

E512 It also finds use as a catalyst between acetone and hydrogen peroxide to form the tetrameric form of acetone peroxide.

E512 also finds wide use as a reducing agent. This is seen in its use for silvering mirrors, where silver metal is deposited on the glass:

Sn2+ (aq) + 2 Ag+ → Sn4+ (aq) + 2 Ag (s)

A related reduction was traditionally used as an analytical test for Hg2+(aq). For example, if SnCl2 is added dropwise into a solution of mercury(II) chloride, a white precipitate of mercury(I) chloride is first formed; as more SnCl2 is added this turns black as metallic mercury is formed. Stannous chloride can be used to test for the presence of gold compounds. SnCl2 turns bright purple in the presence of gold (see Purple of Cassius).

When mercury is analyzed using atomic absorption spectroscopy, a cold vapor method must be used, and E512 is typically used as the reductant.

Inorganic chemistry, SnCl2 is mainly used in the Stephen reduction, whereby a nitrile is reduced (via an imidoyl chloride salt) to an imine which is easily hydrolysed to an aldehyde.