|Producer||Principal applications||Product Form||Packaging|
|Trace elements total (Pt, Pd, Ir, Ru)||0.010||0.020||0.030|
|Loss on ignition||0.010||0.010||0.020|
|Latin name||Rhodium (Rh)|
|Group in Mendeleev's periodic table||VIII|
|Melting point||t 1,963 °С|
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.