| Description |
Metal is lustrous, silvery, and fairly soft when pure.
Usually obtained as gray powder. Used in alloys, electrodes, catalysts,
and as the sulfide, lubricants. Diagnostic tests:
On charcoal molybdenum sulfide gives near the assay a copper-red stain in oxidizing
flame and white oxide further away.
On plaster, mixed with KI, gives a deep ultramarine blue color after
heating with the flame.
Bead tests using sodium phosphate (Na3PO4) gives a
yellowish green color (hot) and nearly colorless (cold), the reducing
flame color is a fine green.
Molybdates (MoO42-) are tested by adding powdered
sample to a dry test tube with a scrap of paper, adding a few drops of
water and an equal amount of concentrated H2SO4. The
mixture is carefully heated until the acid fumes. Cool or slowly add water
and the solution will assume a deep blue color.
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