Maleic anhydride is obtained by distilling fumaric acid with phosphorus pentoxide.
The lower part of the whole apparatus was inclosed in a thick walled vessel, e, containing a layer of phosphorus pentoxide.
The selenide was collected and dried in an atmosphere of nitrogen, and then in a vacuum, in presence of phosphorus pentoxide.
When heated with phosphorus pentoxide it yields acetone, water and some pseudo-cumene.
The phosphorus combines with the oxygen to form an oxide of phosphorus, known as phosphorus pentoxide.