18. A certain compound has an empirical formula of NH2O. Its molar mass is between 55 and 65 g/mol. Its molecular formula is (A) NH2O (B) N2H4O2 (C) N3H6O3 (D) not calculable

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