Manganese metal is produced from the manganese (III) oxide, Mn2O3, which is found in manganite, a manganese ore. The manganese is reduced from its +3 oxidation state in Mn2O3 to the zero oxidation state of the uncharged metal by reacting the Mn2O3 with a reducing agent such as aluminum or carbon. How many pounds of manganese are in 1.261 tons of Mn2O3? (1 ton = 2000 pounds)

About 40 different substances called organophosphorus compounds are registered in the United States as insecticides. They are considered less damaging to the environment than some other insecticides because they breakdown relatively rapidly in the environment. The first of these organophosphorus insecticides to be produced was tetraethyl pyrophosphate, TEPP, which is 33.11% carbon, 6.95% hydrogen, 38.59% oxygen, and 21.35% phosphorus. It has a molecular mass of 290.190. What is the molecular formula for TEPP?