Explanatory notes
… Most oxides of non‑metals are anhydrides. This sub‑Chapter covers inorganic oxygen compounds of non‑metals (anhydrides … molybdenum, tungsten and vanadium). In certain cases, however, they fall elsewhere, e.g., in heading 28.43 … sodium chloride. It is easily liquefied under pressure and very soluble in water. It is presented under pressure in …