The presence in a metal of even small proportions of arsenide generally leads to considerable deterioration in mechanical qualities.
An antimony phosphide and arsenide are known, as is also a thiophosphate, SbPS 4, which is prepared by heating together antimony trichloride and phosphorus pentasulphide.
Arsenic trihydride (arsine or arseniuretted hydrogen), AsH3, is formed by decomposing zinc arsenide with dilute sulphuric acid; by the action of nascent hydrogen on arsenious compounds, and by the electrolysis of solutions of arsenious and arsenic acids; it is also a product of the action of organic matter on many arsenic compounds.
Arsenic forms two hydrides: - The dihydride, As2H2, is a brown velvety powder formed when sodium or potassium arsenide is decomposed by water.
It occurs in the uncombined condition and alloyed with iron in meteorites; as sulphide in millerite and nickel blende, as arsenide in niccolite and cloanthite, and frequently in combination with arsenic and antimony in the form of complex sulphides.