AP Chemistry Name ____________________________________ Period ___ Date ___/___/___ 3 ( Molecules and Compounds STUDY QUESTIONS and PROBLEMS 1. a. How many moles are present in 128 grams of sulfur dioxide? b. What is the mass of 3 moles of oxygen molecules? c. If 5 moles of a metallic element have a mass of 200 grams, which element is it? d. What is the molar mass of methane CH4? e. What is the mass of 9 moles of fluorine molecules? f. 102 grams of a gas contains 6 moles. What is its molar mass? g. How many grams are there in one mole of benzene C6H6? h. How many moles of nitrogen atoms are there in 6 moles of TNT (trinitrotoluene CH3C6H2(NO2)3)? i. What is the molar mass of TNT? 2. What is the percent by mass of nitrogen in ammonium nitrate?