Obtained by reaction of nascent hydrogen with MoO3 . Fifty ml. of distilled water and 10 ml. of cone. HC1, followed by 3 g. of analytically pure zinc granules, are added to 10 g. of MoO3. The mixture is left standing overnight; the blue precipitate is then filtered off, washed until no chloride reaction is evident, and dried over P3O5.
