The plastics industry uses a large amount of Phthalic anhydride, CaHO,, made by the controlled oxidation of naphthalene. 2C10Ha +9 O, > 2 C.H.O, +4 CO; + 4 H20 Since some of the naphthalene is oxidized to other products, only 70.4% of the maximum yield predicted by the equation is actually obtained. How much phthalic anhydride would be produced in practice by oxidation of 200 Ib of naphthalene, C10He.