NAME: __________________________________ DATE: ______________ PERIOD: _____ Honors Chemistry Unit 5 Review Part 1: Molar Conversions, Empirical and Molecular Formulas Review Solve the following problems and show all of your work on a separate sheet of paper. Please remember to use the specific representative particle in your final answers. 1. How many representative particles are in 2.73 x 10-2 mol of MgCl2? 2. If there are 2.35 x 1023 representative particles of gold in gold bar, how many grams would the gold bar weigh? Determine the mass for each of the following: 3. 3.65 x 10-2 mol K2SO4 4. 2.61 mol H2O2 What is the percent composition of each of the following? 5. Cr2O3 6. Mn2P2O 7. HgS 8. Ca(NO3)2 Determine the empirical formula of the compound with the percent composition of: 9. 29.1%, Na, 40.5% S, and 30.4% O. 10. 72.4% Fe and 27.6 % O Determine the molecular formula of each of these compounds. 11. 40.0% C, 53.4% O, and 6.6% H. The molar mass is 120.0 g/mol. 12. 54.5% C, 13.6% H, and 31.8% N. The molar mass is 88.0 g/mol. Part 2: Stoichiometry Review 13. a. Balance the following equation to determine the molar ratios. ______KClO3 ------ ______ KCl + ______ O2 b. Create a statement that relates the amount of reactant to products using the mole ratios. Answer each of the following questions showing all of the work (on a separate piece of paper) and expressing the answers in the correct number of significant figures. 14. KI + H2O2 ----- KOH + I2 a. Balance the equation above. b. How many moles of potassium hydroxide will be produced if 16 moles of potassium are available for the reaction? iodide c. How many molecules of diatomic iodine are produced if 3.58 grams of hydrogen peroxide are available for the reaction? 15. C4H10 + O2 -------- CO2 + H2O a. Balance the equation above. b. How many moles of oxygen are required to burn 4.8 moles of butane completely? c. How many liters of CO2 are produced when 88.0 grams of O2 are reacted with an excess of butane? 16. Al + H3PO4 ----- AlPO4 + H2 a. Balance the equation above. b. What is the limiting reactant when 100.0 grams of H3PO4 react with 25.0 grams of Al? c. How much excess reactant remains? 17. For the reaction between Mercury (II) nitrate and potassium chromate… a. Write the balanced chemical equation b. How many grams of each product will be produced from 38.5 grams of mercury (II) nitrate? (Show work for both products) 18. When 312.7 g of Al2(SO4)3 react with plenty of magnesium, what is the percent yield when 38.5 g of aluminum are formed? 19. If 42.4g of Al react with excess O2 and 67.3g of Al2O3 are produced, what was the percent yield of Al2O3? Note: the balanced equation is: 4 Al + 3 O2  2 Al2O3