1. P 2 O 5 2. P 5 O 2 3. P 10 O 4 4. P 4 O 10

Teacher: Mr. gerraputa Print Close Name: 1. A chemical formula is an expression used to represent 1. mixtures, only 3. compounds, only 2. elements, only 4. compounds and elements 2. What is the total number of moles of atoms in one mole of (NH 4 ) 2 SO 4? 1. 10 3. 14 2. 11 4. 15 3. Given the equation: FeCl 2 + Na 2 CO 3 FeCO 3 + NaCl When the equation is correctly balanced using the smallest whole numbers, the coefficient of NaCl is 1. 6 3. 3 2. 2 4. 4 4. In the compound Al 2 O 3, the ratio of aluminum to oxygen is? 1. 2 grams of aluminum to 3 grams of oxygen 2. 3 grams of aluminum to 2 grams of oxygen 3. 2 moles of aluminum to 3 moles of oxygen 4. 3 moles of aluminum to 2 moles of oxygen 5. What is the total number of atoms of oxygen in the formula Al(ClO 3 ) 3. 6H 2 O? 1. 6 3. 10 2. 9 4. 15 6. Which quantity is equivalent to 39 grams of LiF? 1. 1.0 mole 3. 0.50 mole 2. 2.0 mole 4. 1.5 mole 7. What is the percent by mass of oxygen in Fe 2 O 3 (formula mass = 160)? 1. 16% 3. 56% 2. 30.% 4. 70.% 8. What is the molecular formula of a compound with the empirical formula P 2 O 5 and a gram-molecular mass of 284 grams? 1. P 2 O 5 2. P 5 O 2 3. P 10 O 4 4. P 4 O 10 Page 1 of 7

9. What is the total number of moles of oxygen atoms present in one mole of Mg(ClO 3 ) 2? 1. 5 3. 3 2. 2 4. 6 10. When the equation C 8 H 16 + O 2 CO 2 + H 2 O is correctly balanced using the smallest whole number coefficient, the coefficient of O 2 is 1. 1 3. 12 2. 8 4. 16 11. Which substance has the same molecular and empirical formulas? 12. 1. C 6 H 4 2. C 2 H 4 3. CH 4 4. C 6 H 12 O 6 Which equation illustrates conservation of mass? 1. H 2 + Cl 2 HCl 2. H 2 + Cl 2 2HCl 3. H 2 + O 2 H 2 O 4. H 2 + O 2 2H 2 O 13. What is the total mass of oxygen in 1.00 mole of Al 2 (CrO 4 ) 3? 1. 192 g 3. 64.0 g 2. 112 g 4. 48.0 g 14. Which quantity is represented by the symbol Ne? 15. 1. 1 gram of neon 2. 1 liter of neon 3. 1 mole of neon 4. 1 atomic mass unit of neon When the equation: Al 2 (SO 4 ) 3 + ZnCl 2 AlCl 3 + ZnSO 4 is correctly balanced using the smallest whole number coefficients, the sum of the coefficients is 1. 9 3. 5 2. 8 4. 4 16. Given the unbalanced equation: Ca(OH) 2 + (NH 4 ) 2 SO 4 CaSO 4 + NH 3 + H 2 O What is the sum of the coefficients when the equation is completely balanced using the smallest whole-number coefficients? 1. 5 3. 9 2. 7 4. 11 Page 2 of 7

17. Which is an empirical formula? 1. H 2 O 2 2. H 2 O 3. C 2 H 2 4. C 3 H 6 22. Vitamin C has an empirical formula of C 3 H 4 O 3 and a molecular mass of 176. What is the molecular formula of Vitamin C? 1. C 3 H 4 O 3 2. C 6 H 8 O 6 3. C 9 H 12 O 9 4. C 10 H 8 O 3 18. What is the gram formula mass of Li 2 SO 4? 1. 54g 3. 110g 2. 55g 4. 206g 19. Given the reaction: Ca + 2H 2 O Ca(OH) 2 + H 2 What is the total number of moles of Ca needed to react completely with 4.0 moles of H 2 O? 1. 1.0 3. 0.50 2. 2.0 4. 4.0 20. The percent by mass of Ca in CaCl 2 is equal to 1. (40/111) 100 3. (3/1) 100 2. (111/40) 100 4. (1/3) 100 21. What is the formula mass of Al 2 (SO 4 ) 3? 23. What is the percent by mass of sulfur in sulfur dioxide? 1. 32 3. 50 2. 33 4. 67 24. Given the reaction: CH 4 (g) + 2O 2 (g) CO 2 (g) + 2H 2 O(g) How many moles of oxygen are needed for the complete combustion of 3.0 moles of CH 4 (g)? 1. 6.0 moles 3. 3.0 moles 2. 2.0 moles 4. 4.0 moles 25. How many moles of N 2 (g) would contain exactly 4.0 moles of nitrogen atoms? 1. 1.0 3. 3.0 2. 2.0 4. 4.0 26. 1. 123 3. 214 2. 150. 4. 342 What is the gram formula mass of (NH 4 ) 2 SO 4? 1. 66.0 g 3. 114 g 2. 94.0 g 4. 132 g Page 3 of 7

27. What is the percent by mass of nitrogen in the compound NH 4 NO 3 (formula mass = 80.)? 1. 5.7% 3. 29% 2. 18% 4. 35% 28. What is the total mass in grams of 0.75 mole of SO 2? 1. 16 g 3. 32 g 2. 24 g 4. 48 g 29. Given the reaction: 2Al + 3H 2 SO 4 3H 2 + Al 2 (SO 4 ) 3 The total number of moles of H 2 SO 4 needed to react completely with 5.0 moles of Al is 1. 2.5 moles 3. 7.5 moles 2. 5.0 moles 4. 9.0 moles 30. What is the total number of hydrogen atoms required to form one molecule of C 3 H 5 (OH) 3? 1. 1 3. 3 2. 5 4. 8 31. What is the gram formula mass of Ca 3 (PO 4 ) 2? 1. 135 g/mol 3. 278 g/mol 2. 215 g/mol 4. 310. g/mol 32. Given the unbalanced equation: N 2 (g) + H 2 (g) NH 3 (g) When the equation is balanced using the smallest whole-number coefficients, the ratio of moles of hydrogen consumed to moles of ammonia produced is 1. 1:3 3. 3:1 2. 2:3 4. 3:2 33. An example of an empirical formula is 34. 1. C 4 H 10 2. C 6 H 12 O 6 3. HC 2 H 3 O 2 4. CH 2 O What is the empirical formula of the compound whose molecular formula is P 4 O 10? 35. 1. PO 2. PO 2 3. P 2 O 5 4. P 8 O 20 What is the gram formula mass of K 2 CO 3? 1. 138 g 3. 99 g 2. 106 g 4. 67 g 36. What is the percent by mass of oxygen in magnesium oxide, MgO? 1. 20% 3. 50% 2. 40% 4. 60% Page 4 of 7

37. Given the reaction: CH 4 + 2O 2 CO 2 + 2H 2 O What amount of oxygen is needed to completely react with 1 mole of CH 4? 1. 2 moles 3. 2 grams 2. 2 atoms 4. 2 molecules 38. If an equation is balanced properly, both sides of the equation must have the same number of 1. atoms 3. molecules 2. coefficients 4. moles of molecules 39. A hydrated salt is a solid that includes water molecules within its crystal structure. A student heated a 9.10-gram sample of a hydrated salt to a constant mass of 5.41 grams. What percent by mass of water did the salt contain? 1. 3.69% 3. 40.5% 2. 16.8% 4. 59.5% 40. Given the unbalanced equation: What is the coefficient of O 2 when the equation is balanced correctly using the smallest whole-number coefficients? 1. 1 3. 3 2. 2 4. 4 41. Given the reaction: C 6 H 12 O 6 (s) + 6O 2 (g) 6CO 2 (g) + 6H 2 (l) How many moles of C 6 H 12 O 6 (s) are needed to produce 24 moles of carbon dioxide? 1. 1.0 mole 3. 24 moles 2. 12 moles 4. 4.0 moles 42. What is the percent by mass of oxygen in Ca(OH) 2? [formula mass = 74.1] 1. 21.6% 3. 45.9% 2. 43.2% 4. 54.1% 43. The gram-formula mass of (NH 4 ) 2 CO 3 is 1. 46.0 g 3. 78.0 g 2. 64.0 g 4. 96.0 g 44. What is the total number of moles of atoms contained in 1 mole of NH 3? 1. 1 mole 3. 3 moles 2. 2 moles 4. 4 moles 45. Which equation is correctly balanced? 1. H 2 + O 2 H 2 O 2. Ca + Cl 2 CaCl 3. 2H 2 + O 2 2H 2 O 4. Ca + Cl 2 Ca 2 Cl Page 5 of 7

46. What is the molecular formula of a compound that has a molecular mass of 54 and the empirical formula C 2 H 3? 50. Base your answer on the balanced chemical equation: 47. 1. C 2 H 3 2. C 4 H 6 3. C 6 H 9 4. C 8 H 12 What is the total number of moles of O 2 produced when 8 moles of H 2 O is completely consumed? Answer: mol What is the empirical formula of a compound with the molecular formula N 2 O 4? 1. NO 2. NO 2 3. N 2 O 4. N 2 O 3 48. Given the reaction: What is the mole-to-mole ratio between nitrogen gas and hydrogen gas? 1. 1:2 3. 2:2 2. 1:3 4. 2:3 49. What is the empirical formula for the compound C 6 H 12 O 6? 1. CH 2 O 2. C 2 H 4 O 2 3. C 3 H 6 O 3 4. C 6 H 12 O 6 Page 6 of 7

Answer Key for Chemical calculations review 1. 4 18. 3 35. 1 2. 4 19. 2 36. 2 3. 2 20. 1 37. 1 4. 3 21. 4 38. 1 5. 4 22. 2 39. 3 6. 4 23. 3 40. 3 7. 2 24. 1 41. 4 8. 4 25. 2 42. 2 9. 4 26. 4 43. 4 10. 3 27. 4 44. 4 11. 3 28. 4 45. 3 12. 2 29. 3 46. 2 13. 1 30. 4 47. 2 14. 3 31. 4 48. 2 15. 1 32. 4 49. 1 16. 2 33. 4 50. 4 17. 2 34. 3 Page 7 of 7