Lithium Thioarsenates

Lithium Orthothioarsenate, Li₃AsS₄.nH₂O, is precipitated when alcohol is added to an aqueous solution of the pyro-salt; it forms colourless crystals which are soluble in water. If alcohol is added to the solution of the ortho-salt, lithium metathioarsenate, LiAsS₃, is precipitated. Lithium pyrothioarsenate, Li₄As₂S₇, separates as citron-yellow crystals when an aqueous solution of lithium monohydrogen orthoarsenate, saturated with hydrogen sulphide, is allowed to evaporate. The crystals are stable in the air.