Rhodium

Rhodium is primarily used as an alloying element to palladium, platinum, and nickel. It hardens these materials as well as providing increased corrosion resistance. Platinum containing rhodium is used in crucibles, furnace windings, thermocouples, and oxidation catalysts for HNO3 and ammonia production. Thin coatings of rhodium have been used on glass to produce high reflectivity mirrors and gray filters. Rhodium is slowly attacked by sodium hypochlorite solutions at room temperature but is resistant to most all other solutions including aqua regia and concentrated acids. At 100ºC, it is attacked by sulfuric and bromic acids.