2 CO2 + 2 H2O What mass of CO2 is formed from 1 kg of ethanol? What kind of question is this? Stoichiometry 1.913 kg 9. Vitamin K contains 78.95% C, 3.95% H, and 21.05% O by mass. What is its empirical formula? What kind of question is this? Empirical formula calculation C5H3O 10. Given that vitamin K (see question 9) has molecular weight of 158.15 g/mol, what is its molecular formula? What kind of question is this? 11. When sand is stirred up in a glass of water a (homogeneous of heterogeneous?) Mixture is formed. What kind of question is this? Types of mixtures heterogeneous 12. If 10.0 g of hydrochloric acid is dissolved in enough water to make 1.00 liter of solution, what is the molarity of the solution? What kind of question is this? Concentration 0.274M 13. Balance the following chemical equation: ____ BCl3 + ____H2O ____ B(OH)3 + ____HCl What kind of question is this? Equation-balancing BCl3 + 3 H2O B(OH)3 + 3 HCl 14. A microwave oven used radiation at a frequency