- Autocatalysts manufacturing industry
- Chemical industry
- Electrical industry
- Glass industry
Packaging: Plastic containers KT-2 301 х 241 х 130 mm
Physical and chemical characteristics:
- Latin name Rhodium (Rh)
- Chemical element of Group VIII in Mendeleev's periodic table
- Atomic number 45
- Atomic weight 102.9055
- Density 12.41 g/cmі
- Melting point 1,963°C
A bluish-white metal resembling aluminium, hard and fragile. Highly reflective, becomes more flexible when heated.
Rhodium is chemically resistant. Under normal conditions it does not oxidize in air and in water. When heated it gets covered by a black film of oxide, which disappears at temperatures higher than 1,200°C. Rhodium is resistant to the effects of acids (with the exception of concentrated sulphuric acid) and aqua regia, as well as sulphur, chlorine and fluorine.
It is one of the platinum group metals.
Rhodium was discovered in 1804 by the British scientist William Hyde-Woollaston, immediately after his discovery of palladium. Woollaston dissolved virgin platinum in aqua regia, and then neutralized the excess acid with caustic soda. From the neutralised solution, he precipitated platinum with ammonium chloride, and palladium with mercury cyanide. The filtrate, processed with muriatic acid to get rid of the excess of mercury cyanide, was boiled dry. The residue, after having been treated with alcohol, turned out to be a dark red powder of double sodium rhodium salts of muriatic acid (chloride). The metal is then easily obtained by heating this powder in a stream of hydrogen.
Rhodium gets its name from the Greek "rhodon", which means "rose", on account of the pinkish red colour of its salts.
The main rhodium consumption sector is automotive industry. The metal has a high catalytic activity and is used in making exhaust catalytic converters. As the catalyst, it is used in chemical industry, including production of nitric acid. Due to its resistance to aggressive environments and high temperatures rhodium is used in manufacturingof laboratory glassware, and stability of thermoelectric properties and high infusibility makes it possible to use it in manufacturing of thermocouples for measuring high temperatures. Rhodium is required in manufacturing of liquid crystal displays and glass fibers. Due to its high reflective power it is used in manufacturing of technical mirrors coatings and astronomical instruments.