PRE-LAB QUESTIONS 1. A compound is found to have the empirical formula CH. If the molar mass of the compound is 78.11g/mol, what is the molecular formula of that compound? 2. In the empirical formula experiment, if the Mg starts to burn too rapidly, smoke is given off. What should be done to control this? 3. In Step 1, you are told to heat the crucible before adding anything to it. Why? 4. Most common fire extinguishers use either water or carbon dioxide. In the event of a magnesium fire, would these be OK to use? What section of the MSDS provides details of this information? 5. In the empirical formula experiment, water is added after the initial reaction with oxygen before reheating. Why? Write a balanced reaction describing this. 6. What are the hazards associated with magnesium and magnesium oxide? 7. In Step 2, you are told to "clean" the surface of the magnesium ribbon with steel wool if the magnesium surface is dull. Why