Unit Two Worksheet WS DC U2 Name Period Short Answer [Writing]. Write skeleton equations representing the following reactions and then balance them. Then identify the reaction type. Include all needed symbols for states of matter and catalysts. 1. Solid iron (III) oxide and hydrogen gas react to produce iron metal and liquid water. 2. When nitric acid is poured into magnesium hydroxide solution, a reaction occurs in which magnesium nitrate and water are produced. 3. When barium metal is dropped into hydrochloric acid, barium chloride is created with hydrogen gas being given off. 4. Aqueous sodium chloride and sulfuric acid react to yield sodium sulfate and hydrochloric acid, both of which are aqueous. 5. Solid phosphorus reacts with oxygen gas to produce solid diphosphorus pentoxide. page 1 WS DC U2
6. Pure copper metal can be produced by heating solid copper (II) sulfide in the presence of oxygen gas from the air. Sulfur dioxide gas is also produced in this reaction. 7. Metal iron reacts with oxygen gas to produce solid iron (III) oxide. 8. Aqueous potassium hydroxide and aqueous barium chloride will react to produce aqueous potassium chloride and solid barium hydroxide. 9. Metal barium reacts with aqueous silver nitrate to produce metal silver and aqueous barium nitrate. 10. Sulfur dioxide gas reacts with oxygen gas to produce sulfur trioxide gas. 11. Aluminum metal will react with copper (II) sulfate solution to produce copper metal and aluminum sulfate solution. page 2 WS DC U2
12. Solid silver oxide is heated to produce solid silver and oxygen gas. 13. Aqueous solutions of cadmium bromide and sodium sulfide react to produce aqueous sodium bromide and solid cadmium sulfide. Short Answer [Writing]. Balance the following chemical reactions by filling in the coefficients as needed. If no coefficient is needed, write 1 in the blank. Then identify the reaction type. 14. N 2 O 5 + H 2 O HNO 3 Balanced equation: N 2 O 5 + H 2 O HNO 3 15. P + O 2 P 2 O 5 Balanced equation: P + O 2 P 2 O 5 16. Fe(OH) 3 Fe 2 O 3 + H 2 O Balanced equation: Fe(OH) 3 Fe 2 O 3 + H 2 O 17. NiCO 3 NiO + CO 2 Balanced equation: NiCO 3 NiO + CO 2 18. H 2 + Fe 3 O 4 Fe + H 2 O Balanced equation: H 2 + Fe 3 O 4 Fe + H 2 O page 3 WS DC U2
19. Fe + Cl 2 FeCl 3 Balanced equation: Fe + Cl 2 FeCl 3 20. NaOH + HCl NaCl + H 2 O Balanced equation: NaOH + HCl NaCl + H 2 O 21. Al + H 2 SO 4 Al 2 (SO 4 ) 3 +H 2 Balanced equation: Al + H 2 SO 4 Al 2 (SO 4 ) 3 + H 2 22. NH 4 NO 3 N 2 O + H 2 O Balanced equation: NH 4 NO 3 N 2 O + H 2 O 23. Zn + AgNO 3 Zn(NO 3 ) 2 + Ag Balanced equation: Zn + AgNO 3 Zn(NO 3 ) 2 + Ag Short Answer. Complete the reaction, including indicating states of matter correctly. Then balance the reaction. Finally, identify the kind of reaction. 24. Pb(NO 3 ) 2 (aq) + H 2 SO 4 (aq) 25. Cu (s) + AgNO 3 (aq) 26. Al 2 (SO 4 ) 3 (aq) + NH 4 OH (aq) page 4 WS DC U2
27. Br 2 (aq) + FeI 3 (aq) 28. Fe(NO 3 ) 3 (aq) + NaOH (aq) 29. H 2 SO 4 (aq) + BaCl 2 (aq) 30. Sr (s) + N 2 (g) 31. CaCl 2 (aq) + Pb(NO 3 ) 2 (aq) 32. Ca (s) + O 2 (g) Short Answer. Answer the following questions. 33. How is the law of conservation of mass related to the balancing of a chemical equation? 34. Explain why the following is true: 2Na + 2HCl 2NaCl + H 2 Ag + HCl No reaction page 5 WS DC U2
35. How do you show, in a chemical equation, that the reaction is reversible? 36. What information would be lost in the description of a chemical reaction if chemical formulas were not used in chemical equations? 37. How can the ability to predict formulas from ionic charge be helpful in predicting the products of a chemical reaction? 38. The equation for the formation of water from its elements, H 2 (g) + O 2 (g) H 2 O (l), can easily be balanced by changing the formula of the product to H 2 O 2. Explain why this is incorrect. 39. How do you predict the correct formula for the combination reaction between a Group A metal and a nonmetal? Calculations. Answer the following questions. Show work or receive no credit. Include proper units and significant figures. Find the gram formula mass or gram molecular mass of each compound. 40. Li 2 O (lithium oxide) 42. C 6 H 12 O 6 (fructose) 41. (NH 4 ) 2 SO 3 (ammonium sulfite) 43. Fe(OH) 3 (iron (III) hydroxide) page 6 WS DC U2
44. NH 4 NO 3 (ammonium nitrate) 45. FeCl 3 (iron (III) chloride) How many oxygen atoms are in a representative particle of each substance? 46. N 2 O 5 (dinitrogen pentoxide) 47. NH 4 NO 3 (ammonium nitrate) 48. C 3 H 5 (NO 3 ) 3 (nitroglycerin) 49. C 6 H 5 COOH (benzoic acid) 50. C 8 H 8 O 4 (acetylsalicylic acid) 51. Al(OH) 3 (aluminum hydroxide) Make the following conversions. Show work or receive no credit. Include proper units and significant figures. 52. Convert 2.51 10 24 molecules NH 3 to moles NH 3. 53. Convert 1 trillion (1 10 12 ) molecules O 2 to moles O 2. 54. Convert 6.022 10 24 molecules Br 2 to moles of bromine atoms (NOTE: NOT Br 2 ). 55. Convert 5.63 10 24 atoms Li to moles of lithium atoms. page 7 WS DC U2
56. Convert 0.398 mol H 2 O 2 to milligrams H 2 O 2. 57. Convert 6.07 mol Ca(NO 3 ) 2 to grams of Ca(NO 3 ) 2. 58. Convert 26.0 L CH 4, at standard temperature and pressure, into grams of CH 4. 59. Convert 779 cg SnF 2 into number of formula units of SnF 2. 60. Convert 0.0273 g Li 2 HPO 4 into the number of atoms in Li 2 HPO 4. 61. Convert 4.57 10 22 molecules Cl 2, at standard temperature and pressure, into volume, in milliliters, of Cl 2. page 8 WS DC U2
62. Convert 0.77 mol C 2 H 6, at standard temperature and pressure, into volume, in liters, of C 2 H 6. 63. Convert three molecules of aspirin (C 9 H 8 O 4 ) into nanograms of aspirin. 64. Convert 19.9 g SiO 2 into the number of formula units of SiO 2. 65. Moles of 1090 g Ca(C 2 H 3 O 2 ) 2 Answer the following questions, showing relevant work to receive credit, significant figures, and proper units. 66. Find the density of C 3 H 8 (g) at standard temperature and pressure. 67. Find the density of NO 2 (g) at standard temperature and pressure. 68. The densities of gases A, B, and C are 1.25 g/l, 2.86 g/l, and 0.714 g/l, respectively, at standard temperature and pressure. Calculate the molar mass of each substance (in other words, find the molar mass of gas A, gas B, and gas C). Then identify each substance as ammonia (NH 3 ), sulfur dioxide (SO 2 ), chlorine (Cl 2 ), nitrogen (N 2 ), or methane (CH 4 ). Show work or receive no credit. page 9 WS DC U2
Complete the following table. Show relevant work in the box or receive no credit, and circle your final answer in the box. Also include proper units and significant figures. Formula of substance involved Grams dissolved Moles dissolved 72. Volume of solution 76. Molarity LiCl 15.00 g 0.200 L 69. 73. Fe(NO 3 ) 3 1.00 L 1.00 M 70. 75. Na 3 PO 4 0.035 mol 1.50 M 71. 74. Na 2 SO 4 300 ml 2.4 x 10 2 M page 10 WS DC U2
Calculate the percent composition of the compounds that are formed from the following reactions, showing relevant work or receiving no credit, significant figures, and proper units. 77. 222.6 g N combines completely with 77.4 O 78. 2.62 g Na and 4.04 g Cl are formed by the decomposition of table salt The compound methyl butanoate has a percent composition of 58.8% C, 9.8% H, and 31.4% O. 79. What is methyl butanoate s empirical formula? 80. If methyl butanoate s molar mass is 102 g/mol, what is its molecular formula? page 11 WS DC U2
A compound with a mass of 7.36 g has 6.93 g of oxygen while the rest of the mass is hydrogen. 81. What is the compound s empirical formula? 82. If the compound s molar mass is 34.0 g/mol, what is its molecular formula? Calculate the amount of hydrogen, in grams, in the following amounts of the following compounds assuming 225 g of each substance are present. 83. KC 2 H 3 O 2 (potassium acetate) 84. C 12 H 22 O 11 (sucrose, or table sugar) page 12 WS DC U2
85. A compound s percent composition is 32.00% C, 42.66% O, 18.67% N, and 6.67 % H. If the molar mass of this compound is 146.103 g/mol, what is the molecular formula of this compound? Show work or receive no credit. 86. Nitroglycerine contains 60% as many carbon atoms as hydrogen atoms; three times as many oxygen atoms as nitrogen atoms; and the same number of carbon and nitrogen atoms. The number of moles of nitroglycerine in 1 g is 0.00441. What is the molecular formula of nitroglycerine? Show work or receive no credit. Short Answer. Answer the following questions. 87. Would four balloons, each containing the same number of molecules of a different gas at standard temperature and pressure, have the same mass or the same volume? Explain. 88. How can you determine the molar mass of a gaseous compound if you do not know its molecular formula? 89. Why might the term molar mass be used instead of gram molecular mass, gram formula mass, or gram atomic mass? page 13 WS DC U2