17. A hydrocarbon has the formula C5H12. What is the percent by mass of carbon in the compound? (A) 83.2 % (B) 41.6 % (C) 16.8 % (D) 29.4 % (E) 15.7 %

22. Consider that calcium metal reacts with oxygen gas in the air to form calcium oxide. Suppose we react 6.02 mol calcium with 4.00 mol oxygen gas. Determine the number of moles of calcium oxide produced after the reaction is complete.(A) 6.02 mol CaO (B) 3.01 mol CaO (C) 4.01 mol CaO(D) 8.00 mol CaO (E) none of these