Used as a catalyst in petroleum refining and chemical synthesis, particularly in hydrodesulfurization processes to remove sulfur from fuels. Employed in the production of molybdenum metal and alloys, which are essential for high-strength steels and corrosion-resistant materials. Applied in analytical chemistry as a reagent for the detection and determination of phosphates, silicates, and arsenates in water and soil samples. Utilized in the manufacture of pigments, corrosion inhibitors, and flame retardants for coatings and plastics. Also serves in biological and environmental research as a source of molybdenum in nutrient media and enzyme studies.