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?