When heated to decomposition, chromium trioxide emits smoke and irritating fumes. Lead chromate occurs as yellow or orange monoclinic crystals that are insoluble in water, acetic acid, and ammonia but are soluble in acid and alkali. Lead chromate, when heated to decomposition, emits toxic fumes of lead. Basic lead chromate is a red amorphous or crystalline powder. It is insoluble in hot and cold water, reacts with most acid and alkali but not with acetic acid or ammonia, and emits very toxic fumes of lead when heated to decomposition.
Strontium chromate occurs as monoclinic yellow crystals.
It is soluble in cold and hot water and reacts with hydrochloric acid, nitric acid, acetic acid, and ammonium salts. Zinc chromate occurs as lemon yellow prisms. It is insoluble in cold water and acetone, dissolves in hot water, and is soluble in acid and liquid ammonia. The steel industry is the major consumer of chromium. Chromium is used as an alloying and plating element on metal and plastic substrates for corrosion resistance in chromium- containing and stainless steels and in protective coatings for automotive and equipment accessories.