Name: ________________________________________ Date: ____________ Unit 3 Review Molar Mass: Determine the molar mass of the following compounds. 1. Potassium nitrate 3. Lithium dichromate 2. Ammonium oxide 4. Strontium phosphate Conversions 5. Convert 8.79 x 1022 molecules of dinitrogen pentoxide to moles. 6. Convert 3.7 moles of copper (II) chloride to grams. 7. Convert 8.79 grams of carbon tetrachloride to molecules. 8. Convert 2.76 x 1024 atoms of helium to liters of gas at STP. 9. Determine the volume in mL of sulfuric acid (H2SO4) in 2.50 moles (density: 1.84 g/mL). Period: ______ 10. How many atoms of nitrogen are in 24.5 g of Mg3N2? 11. What volume of Argon gas is present in 3.456 x 1025 atoms of gas at STP? Molarity 12. Determine the mass of potassium bromide required to make 250.0 mL of 1.0 M solution. 13. What volume of 0.75 M AgNO3 can be made from 56.7 grams of solute? Percent Composition 14. Calculate the % Oxygen in each of the following compounds. Na2O N2O5 CH3COOH Empirical and Molecular Formula 15. Caffeine has the following percent composition: carbon 49.48%, hydrogen 5.19%, oxygen 16.48% and nitrogen 28.85%. Its molecular weight is 194.19 g/mol. a. Solve for empirical formula: b. Solve for molecular formula:
