11.2 Types of Chemical Reactions The five general types of reactions are combination, decomposition, singlereplacement,

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1 11 Study Guide 11 Study Guide Study Tip Use Physical Models to Clarify Concepts For example, when balancing chemical equations or classifying a reaction according to its type, physical models of atoms can aid visual learners. Molecular model kits, Styrofoam balls, gumdrops, or modeling clay can be used to represent different types of atoms. If your class subscribes to the Interactive Textbook with ChemASAP, your students can go online to access an interactive version of the Student Edition and a self-test. with ChemASAP Key Concepts 11.1 Describing Chemical Reactions To write a word equation, write the names of the reactants to the left of the arrow separated by plus signs; write the names of the products to the right of the arrow, also separated by plus signs. To write a skeleton equation, write the formulas for the reactants to the left of the yields sign and the formulas for the products to the right. After writing the skeleton equation, use coefficients to balance the equation so that it obeys the law of conservation of mass Types of Chemical Reactions The five general types of reactions are combination, decomposition, singlereplacement, double-replacement, and combustion. The number of elements and/or compounds reacting is a good indicator of possible reaction type and thus possible products. Vocabulary activity series (p. 333) balanced equation (p. 325) catalyst (p. 323) chemical equation (p. 323) coefficients (p. 325) combination reaction (p. 330) combustion reaction (p. 336) complete ionic equation (p. 342) decomposition reaction (p. 332) double-replacement reaction (p. 334) In a combination reaction, there is always a single product. A decomposition reaction involves the breakdown of a single compound into two or more simpler substances. In a single-replacement reaction, both the reactants and the products are an element and a compound. A double-replacement reaction generally takes place between two ionic compounds in aqueous solution. A combustion reaction always involves oxygen as a reactant Reactions in Aqueous Solution A net ionic equation shows only those particles involved in the reaction and is balanced with respect to mass and charge. You can predict the formation of a precipitate by using the general rules for solubility of ionic compounds. net ionic equation (p. 343) single-replacement reaction (p. 333) skeleton equation (p. 323) spectator ion (p. 343) Organizing Information Use these terms to construct a concept map that organizes the major ideas of this chapter. balanced chemical equation reactant skeleton equation Concept Map 11 Solve the Concept Map with the help of an interactive tutorial. withchemasap product coefficient 346 Chapter 11 Chapter Resources Print Core Teaching Resources, Chapter 11, Practice Problems Vocabulary Review, Quiz, Chapter Test A, Chapter Test B Technology Computer Test Bank, Chapter 11 Test Interactive Textbook with ChemASAP, Chapter Chapter 11

2 11 Assessment 11 Assessment Reviewing Content 11.1 Describing Chemical Reactions 36. Identify the reactants and products in each chemical reaction. a. Hydrogen gas and sodium hydroxide are formed when sodium is dropped into water. b. In photosynthesis, carbon dioxide and water react to form oxygen gas and glucose. 37. How did John Dalton explain a chemical reaction using his atomic theory? 38. What is the function of an arrow ( ) in a chemical equation? A plus sign ( )? 39. Write sentences that completely describe each of the chemical reactions shown in these skeleton equations. a. Pt NH 3 1 g 2 + O 2 1 g 2 NO1 g 2 + H 2 O1 g 2 b. H 2 SO 4 (aq) BaCl 2 (aq) BaSO 4 (s) HCl(aq) c. N 2 O 3 (g) H 2 O(l) HNO 2 (aq) 40. What is the purpose of a catalyst? 41. Balance equations for each item. The formula for each product (object) is given. a. a basketball team center forward guard team C F G CF 2 G 2 b. a tricycle frame wheel seat pedal tricycle F W S P FW 3 SP The equation for the formation of water from its elements, H 2 (g) O 2 (g) H 2 O(l), can be balanced by changing the formula of the product to H 2 O 2. Explain why this is incorrect. 43. Balance the following equations. a. PbO 2 PbO O 2 b. Fe(OH) 3 Fe 2 O 3 H 2 O c. (NH 4 ) 2 CO 3 NH 3 H 2 O CO 2 d. NaCl H 2 SO 4 Na 2 SO 4 HCl 11.2 Types of Chemical Reactions 44. What is a characteristic of every combination reaction? 45. Write balanced chemical equations for the following combination reactions. a. Mg O 2 b. P O 2 diphosphorus pentoxide c. Ca S b. Zn(s) +2AgNO 3 (aq) Zn(NO 3 ) 2 (aq) + 2Ag(s) c. 2Al(s) + 3H 2 SO 4 (aq) Al 2 (SO 4 ) 3 (aq) + 3H 2 (g) 49. a. H 2 C 2 O 4 (aq) + 2KOH(aq) K 2 C 2 O 4 (aq) + 2H 2 O(l) b. CdBr 2 (aq) + Na 2 S(aq) CdS(s) + 2NaBr(aq) 50. oxygen 51. a. C 4 H 8 + 6O 2 4CO 2 + 4H 2 O b. C 3 H 6 O + 4O 2 3CO 2 + 3H 2 O 52. a. 3Hf + 2N 2 Hf 3 N 4 ; combination 46. What is a distinguishing feature of every decomposition reaction? 47. Write a balanced chemical equation for each decomposition reaction. a. D Ag 2 O1s2? b. D ammonium nitrate dinitrogen monoxide + water 48. Use the activity series of metals to write a balanced chemical equation for each singlereplacement reaction. a. Au(s) KNO 3 (aq) b. Zn(s) AgNO 3 (aq) c. Al(s) H 2 SO 4 (aq) 49. Write a balanced equation for each of the following double-replacement reactions. a. H 2 C 2 O 4 (aq) KOH(aq) b. CdBr 2 (aq) Na 2 S(aq) (Cadmium sulfide is a precipitate.) 50. What substance is common to all combustion reactions? 51. Write a balanced equation for the complete combustion of each compound. a. butene (C 4 H 8 ) b. acetone (C 3 H 6 O) 52. Balance each equation and identify its type. a. Hf N 2 Hf 3 N 4 b. Mg H 2 SO 4 MgSO 4 H 2 c. C 2 H 6 O 2 CO 2 H 2 O d. Pb(NO 3 ) 2 NaI PbI 2 NaNO 3 e. Fe O 2 Fe 3 O Reactions in Aqueous Solution 53. What is a spectator ion? 54. Write a balanced net ionic equation for the following reactions. a. HCl(aq) Ca(OH) 2 (aq) b. AgNO 3 (aq) AlCl 3 (aq) (Silver chloride is a precipitate.) 55. Complete each equation and then write a net ionic equation. a. Al(s) H 2 SO 4 (aq) b. HCl(aq) Ba(OH) 2 (aq) c. Au(s) HCl(aq) Assessment 347 b. Mg +H 2 SO 4 MgSO 4 + H 2 ; single replacement c. 2C 2 H 6 + 7O 2 4CO 2 + 6H 2 O; combustion d. Pb(NO 3 ) 2 + 2NaI PbI 2 + 2NaNO 3 ; double replacement e. 3Fe + 2O 2 Fe 3 O 4 ; combination 53. an ion that does not participate in the reaction 54. a. H + (aq) + OH (aq) H 2 O(l) b. Ag + (aq) + Cl (aq) AgCl(s) 55. a. 2Al(s) + 6H + (aq) 2Al 3+ (aq) + 3H 2 (g) b. H + (aq) + OH (aq) H 2 O(l) c. no reaction 36. a. reactants: sodium and water; products: hydrogen and sodium hydroxide b. reactants: carbon dioxide and water; products: oxygen and glucose 37. Dalton said that the atoms of reactants are rearranged to form new substances as products. 38. The arrow separates the reactants from the products and indicates a reaction that progresses in the forward direction. A plus sign separates individual reactants and individual products from one another. 39. a. Gaseous ammonia and oxygen react in the presence of a platinum catalyst to produce nitrogen monoxide gas and water vapor. b. Aqueous solutions of sulfuric acid and barium chloride are mixed to produce a precipitate of barium sulfate and aqueous hydrochloric acid. c. The gas dinitrogen trioxide reacts with water to produce an aqueous solution of nitrous acid. 40. A catalyst speeds up a chemical reaction. 41. a. C + 2F + 2G CF 2 G 2 b. F + 3W + S + 2P FW 3 SP A formula is a unique identifier of a substance. A different formula would indicate a different substance, not the one that is taking part in the reaction you are trying to balance. 43. a. 2PbO 2 2PbO + O 2 b. 2Fe(OH) 3 Fe 2 O 3 + 3H 2 O c. (NH 4 ) 2 CO 3 2NH 3 + H 2 O + CO 2 c. 2NaCl + H 2 SO 4 Na 2 SO 4 + 2HCl 44. a single product 45. a. 2Mg + O 2 2MgO b. 4P + 5O 2 2P 2 O 5 c. Ca + S CaS 46. a single reactant 47. a. 2Ag 2 O Δ 4Ag + O 2 b. NH 4 NO 3 Δ 48. a. no reaction N 2 O + 2H 2 O Chemical Reactions 347

3 11 Assessment continued 56. a. Cl 2 + 2NaI 2NaCl + I 2 b. 2NH 3 N 2 + 3H 2 c. 4Na + O 2 2Na 2 O 57. a. Cl 2 (g) + 2KI(aq) I 2 (aq) + 2KCl(aq) b. 2Fe(s) + 6HCl(aq) 2FeCl 3 (aq) + 3H 2 (g) c. P 4 O 10 (s) + 6H 2 O(l) 4H 3 PO 4 (aq) 58. a. ZnS(aq) + H 2 SO 4 (aq) H 2 S(g) + ZnSO 4 (aq) b. NaOH(aq) + HNO 3 (aq) H 2 O(l) + NaNO 3 (aq) c. 2KF(aq) + Ca(NO 3 ) 2 (aq) CaF 2 (s) + 2KNO 3 (aq) 59. a. Na 2 O(s) + H 2 O(l) 2NaOH(aq) b. H 2 (g) + Br 2 (g) 2HBr(g) c. Cl 2 O 7 (l) + H 2 O(l) 2HClO 4 (aq) 60. a. Fe(s) + H 2 SO 4 (aq) FeSO 4 (aq) + H 2 (g) b. no reaction c. Br 2 (l) + BaI 2 (aq) BaBr 2 (aq) + I 2 (aq) 61. a. tube A b. 2Na(s) + 2H 2 O(l) 2NaOH(aq) + H 2 (g) single-replacement 62. a. 2C 8 H O 2 16CO H 2 O b. C 6 H 12 O 6 + 6O 2 6CO 2 + 6H 2 O c. HC 2 H 3 O 2 + 2O 2 2CO 2 + 2H 2 O energy 63 a. 2Al 2 O 3 4Al + 3O 2 b. Sn(OH) 4 SnO 2 + 2H 2 O c. Ag 2 CO 3 Ag 2 O + CO a. H + (aq) + OH (aq) H 2 O(l) b. S 2 (aq) + 2H + (aq) H 2 S(g) c. 3OH (aq) + Fe 3+ (aq) Fe(OH) 3 (s) 65. a. CdS(s) b. Na + (aq) and NO 3 (aq) c. Cd 2+ (aq) + S 2 (aq) CdS(s) 66. a. K 2 O(s) + H 2 O(l) 2KOH(aq); combination b. C 19 H 40 (s) + 29O 2 (g) 19CO 2 (g) + 20H 2 O(l) c. 2Rb(s) + 2H 2 O(l) H 2 (g) + 2RbOH(aq) single-replacement 348 Chapter Assessment continued Understanding Concepts 56. Each equation is incorrect. Find the errors, then rewrite and balance each equation. a. Cl 2 NaI NaCl 2 I b. NH 3 N H 3 c. Na O 2 NaO Write a balanced chemical equation for each reaction. Use the necessary symbols from Table 11.1 to describe the reaction completely. a. Bubbling chlorine gas through a solution of potassium iodide gives elemental iodine and a solution of potassium chloride. b. Bubbles of hydrogen gas and aqueous iron(iii) chloride are produced when metallic iron is dropped into hydrochloric acid. c. Solid tetraphosphorus decoxide reacts with water to produce phosphoric acid. 58. Write balanced chemical equations for these double-replacement reactions that occur in aqueous solution. a. Zinc sulfide is added to sulfuric acid. b. Sodium hydroxide reacts with nitric acid. c. Solutions of potassium fluoride and calcium nitrate are mixed. 59. Write a balanced chemical equation for each combination reaction. a. sodium oxide water b. hydrogen bromine c. dichlorine heptoxide water 60. Write a balanced chemical equation for each single-replacement reaction that takes place in aqueous solution. Write no reaction if a reaction does not occur. a. Steel wool (iron) is placed in sulfuric acid. b. Mercury is poured into an aqueous solution of zinc nitrate. c. Bromine reacts with aqueous barium iodide. 61. Pieces of sodium and magnesium are dropped into separate water-filled test tubes (A and B). There is vigorous bubbling in Tube A, but not in Tube B. a. Which tube contains the sodium metal? b. Write an equation for the reaction in the tube containing the sodium metal. What type of reaction is occurring in this tube? 62. Write a balanced equation for the complete combustion of each compound. Assume that the products are carbon dioxide and water. a. octane (C 8 H 18 ) b. glucose (C 6 H 12 O 6 ) c. acetic acid (HC 2 H 3 O 2 ) 63. Write balanced chemical equations for these decomposition reactions. a. Aluminum is obtained from aluminum oxide with the addition of a large amount of electrical energy. b. Heating tin(iv) hydroxide gives tin(iv) oxide and water. c. Silver carbonate decomposes into silver oxide and carbon dioxide when it is heated. 64. Write a balanced net ionic equation for each reaction. The product that is not ionized is given. a. H 2 C 2 O 4 KOH [H 2 O] b. Na 2 S HCl [H 2 S] c. NaOH Fe(NO 3 ) 3 [Fe(OH 3 )] 65. Aqueous solutions of sodium sulfide and cadmium nitrate were mixed in a beaker. a. Write the formula of the yellow precipitate. b. Identify the spectator ions in the solution. c. Write the net ionic equation for the reaction. 66. Each of these equations has water as either a reactant or a product. Balance each equation and identify the type of those reactions in which water is a reactant. a. K 2 O(s) H 2 O(l) KOH(aq) b. C 19 H 40 (s) O 2 (g) CO 2 (g) H 2 O(l) c. Rb(s) H 2 O(l) H 2 (g) RbOH(aq) 348 Chapter 11

4 Critical Thinking 67. Fill in the missing reactant and then balance each equation. a. K(s) KOH(aq) H 2 (g) b. C 2 H 5 OH(l) CO 2 (g) H 2 O(g) c. Bi(NO 3 ) 3 (aq) Bi 2 S 3 (s) HNO 3 (aq) d. Al(s) AlBr 3 (s) e. HNO 3 (aq) Ba(NO 3 ) 2 (aq) H 2 O(l) 68. Why is smoking not permitted near an oxygen source? What would happen if a match were struck in a room filled with oxygen? 69. Alkanes are hydrocarbon molecules that have the general formula C n H 2n 2. The graph shows the number of oxygen, carbon dioxide, and water molecules needed to balance the equations for the complete combustion of every alkane having from one to ten carbon atoms. C n H 2n 2 O 2 CO 2 H 2 O Coefficients in Combustion Equations Molecules of O 2, CO 2, H 2 O Equation Coefficients Carbon atoms in alkane (n) Carbon dioxide Oxygen Water a. Use the graph to write balanced equations for the combustion of C 5 H 12 and C 9 H 20. b. Extrapolate the graph and write balanced equations for the combustion of C 12 H 26 and C 17 H 36. c. The coefficient for O 2 in the general equation is as follows. n + a n b What are the coefficients for CO 2 and H 2 O? Concept Challenge 70. Write a balanced chemical equation for each reaction. Classify each as to type. a. Sodium iodide reacts with phosphoric acid. b. Potassium oxide reacts with water. c. Heating sulfuric acid produces water, oxygen, and sulfur dioxide. d. Aluminum reacts with sulfuric acid. e. Pentane (C 5 H 12 ) reacts with oxygen. 71. The photos show various types of reactions. (1) (2) (3) (4) (1) Aluminum reacting with bromine (2) The reaction of copper with aqueous silver nitrate (3) Propane (C 3 H 8 ) reacting with oxygen (4) The reaction of lead(ii) nitrate with potassium iodide a. Identify each type of reaction. b. Write the equation for each reaction. 72. When pale yellow chlorine gas is bubbled through a clear, colorless solution of sodium iodide, the solution turns brown. a. What type of reaction is taking place? b. Write the net ionic equation. Assessment a. 2K(s) + 2H 2 O(l) 2KOH(aq) + H 2 (g) b. C 2 H 5 OH(l) + 3O 2 (g) 2CO 2 (g) + 3H 2 O(g) c. 2Bi(NO 3 ) 3 (aq) + 3H 2 S(g) Bi 2 S 3 (s) + 6HNO 3 (aq) d. 2Al(s) + 3Br 2 (l) 2AlBr 3 (s) e. 2HNO 3 (aq) + Ba(OH) 2 (aq) Ba(NO 3 ) 2 (aq) + 2H 2 O(l) 68. Smoking is not permitted near an oxygen source because a fire will burn faster in an area of high oxygen concentration. However, if a match were struck in a room full of oxygen and isolated from combustible material, it would only burn more vigorously. 69. a. C 5 H O 2 5CO 2 + 6H 2 O C 9 H O 2 9CO H 2 O b. 2C 12 H O 2 24CO H 2 O C 17 H O 2 17CO H 2 O c. n = CO 2 ; (n + 1) = H 2 O 70. a. 3NaI + H 3 PO 4 3HI + Na 3 PO 4 ; double-replacement b. K 2 O + H 2 O 2KOH; combination c. 2H 2 SO 4 2H 2 O + O 2 + 2SO 2 ; decomposition d. 2Al + 3H 2 SO 4 3H 2 + Al 2 (SO 4 ) 3 ; single-replacement e. C 5 H O 2 5CO 2 + 6H 2 O; combustion 71. a. (1) combination (2) single-replacement (3) combustion (4) double-replacement b. (1) 2Al(s) + 3Br 2 (l) 2AlBr 3 (s) (2) Cu(s) + 2AgNO 3 (aq) Cu(NO 3 ) 2 (aq) + 2Ag(s) (3) C 3 H 8 (g) + 5O 2 (g) 3CO 2 (g) + 4H 2 O(g) (4) Pb(NO 3 ) 2 (aq) + 2KI(aq) PbI 2 (s) + 2KNO 3 (aq) 72. a. single-replacement b. Cl 2 (g) + 2I (aq) I 2 (aq) + 2Cl (aq) Chemical Reactions 349

5 11 Assessment continued 73. a. water b. water vapor in the air c. physical change 74. Element: gold; compounds: sodium chloride, ice with water; homogeneous mixtures, salt water, air; heterogeneous mixture: salt and sand; substance: sodium chloride, gold, water with ice kg protons, 28 neutrons, and 22 electrons 77. a. 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 b. 1s 2 2s 2 2p 6 3s 2 3p 6 c. 1s 2 2s 2 2p 6 3s 2 3p 6 3d 10 d. 1s 2 2s 2 2p 6 3s 2 3p 6 3d Electronegativity is the tendency for an atom to attract bonded electrons to itself. Electronegativity values increase from left to right in a period. 79. a. incorrect; KBr b. correct c. incorrect; Ca 3 N 2 d. correct 80. a. K 2 CrO 4 b. NaHSO 3 c. permanganic acid d. potassium oxalate 81. a mol b mol c mol d mol 82. a. compound 1: FeSO 4, compound 2: FeSO 3 b. FeSO 4, iron(ii) sulfate; FeSO 3, iron(iii) sulfite 83. C 8 H 10 O 2 N a. CaCl 2 (mol ) H 2 O (mol) a b c d e f g h b. 6 c. Two molecules of water. Water absorbed (mol) 11 Assessment continued Cumulative Review 73. When you take a glass of cold liquid outside on a warm, humid day, drops of liquid soon form on the outside of the glass. (Chapter 2) a. What is the liquid? b. Where did the liquid come from? c. Did a chemical or physical change occur? 74. Classify each of the following as an element, a compound, a homogeneous mixture, a heterogeneous mixture, or a substance. Some may fit in more than one category. (Chapter 2) a. salt water b. salt and sand c. sodium chloride d. gold e. air f. water with ice 75. A block of ice measures 25.0 cm 42.0 cm 38.0 cm. What is the mass of the ice in kilograms? The density of ice is g/cm 3. (Chapter 3) 76. List the number of protons, neutrons, and electrons in this isotope of titanium: Ti (Chapter 4) 77. Write electron configurations for the following ions. (Chapter 5) a. Sr 2 b. S 2 c. Ga 3 d. Cu 78. Explain what is meant by electronegativity. How do electronegativity values change across a row of representative elements? (Chapter 6) 79. Are any of the following formula units for ionic compounds incorrect? If so, write the correct formulas. (Chapter 7) a. K 2 Br b. Na 2 S c. CaN 2 d. Al 2 O Give the name or formula for the following compounds. (Chapter 9) a. Potassium chromate b. Sodium hydrogen sulfite c. HMnO 4 d. K 2 C 2 O Calculate the number of moles in each substance. (Chapter 10) a L of nitrogen dioxide (at STP) b g of magnesium ions c g of sodium hypochlorite d molecules of carbon monoxide 350 Chapter The graphs show the percent composition of two different compounds formed by the elements iron, oxygen, and sulfur. (Chapter 10) Percent Element Percent Composition of Two Compounds Iron Sulfur Oxygen compound 1 compound 2 a. Using the data on the graphs, calculate the empirical formula of each compound. b. Name each compound. 83. Many coffees and colas contain the stimulant caffeine. The percent composition of caffeine is 49.5% C, 5.20% H, 16.5% O, and 28.9% N. What is the molecular formula of caffeine if its molar mass is g/mol? (Chapter 10) 84. Calcium chloride (CaCl 2 ) is a white solid used as a drying agent. The maximum amount of water absorbed by different quantities of CaCl 2 is given in the table below. (Chapter 10) CaCl 2 (g) CaCl 2 (mol) H 2 O (g) H 2 O (mol) 17.3 a b c d. 124 e f. 337 g. 109 h. a. Complete the table. b. Plot the moles of water absorbed (y-axis) versus the moles of CaCl 2. c. Based on your graph, how many molecules of water does each formula unit of CaCl 2 absorb? Calcium chloride (mol) 350 Chapter 11

6 Standardized Test Prep Test-Taking Tip Before you answer questions about a diagram, study the diagram carefully. Read all captions and labels. Look at all the information in the diagram and think about how it all relates together. Ask yourself some questions. What is this diagram showing? What does this diagram tell me? Select the choice that best answers each question or completes each statement. 1. When the equation Fe 2 O 3 H 2 Fe H 2 O is balanced using whole-number coefficients, what is the coefficient of H 2? a. 6 b. 3 c. 2 d Identify the spectator ion in this reaction. Ba(OH) 2 (aq) H 2 SO 4 (aq) BaSO 4 (s) H 2 O(l) a. Ba 2 b. SO 4 2 c. OH d. H e. There is no spectator ion. 3. Magnesium ribbon reacts with an aqueous solution of copper(ii) chloride in a single replacement reaction. Which are the products of the balanced net ionic equation for the reaction? a. Mg 2 (aq) 2Cl (aq) Cu(s) b. Mg (aq) Cl (aq) Cu (aq) c. Mg 2 (aq) Cu(s) d. Cu(s) 2Cl (aq) 7. Which are the expected products of the decomposition reaction of potassium oxide, K 2 O? a. K (s) and O 2 (g) b. K (s) and O 2 (g) c. K(s) and O 2 2 (g) d. K(s) and O 2 (g) Use the diagram to answer Questions Ammonium carbonate Burner Glass tubing Test tube with limewater Rubber tubing 8. When ammonium carbonate is heated, water, ammonia, and carbon dioxide are produced. What type of chemical reaction is occurring? 9. Write formulas for the reaction products. 10. Write a balanced equation for the reaction. Include states for reactants and products. 11. What purpose does the limewater serve? Standardized Test Prep 1. b 2. e 3. c 4. P is calcium nitrate, Q is potassium carbonate, and R is hydrochloric acid. 5. Ca 2+ (aq) + CO 3 2 (aq) CaCO 3 (s) 6. 2K + (aq) + CO 3 2 (aq) + 2H + (aq) + 2Cl (aq) 2K + (aq) + 2Cl (aq) + H 2 O(l) + CO 2 (g) 7. d 8. decomposition reaction 9. H 2 O, NH 3, and CO (NH 4 ) 2 CO 3 (s) 2NH 3 (g) + CO 2 (g) + H 2 O(g) 11. to react with and identify the carbon dioxide 12. (b) represents the reactants (c) represents the products Use the following description and data table to answer Questions 4 6. Dropper bottles labeled P, Q, and R contain one of three aqueous solutions: potassium carbonate, K 2 CO 3 ; hydrochloric acid, HCl; and calcium nitrate, Ca(NO 3 ) 2. The table shows what happens when pairs of solutions are mixed. Solution P Q R P precipitate no reaction Q precipitate gas forms R no reaction gas forms 4. Identify the contents of each dropper bottle. 5. Write the net ionic equation for the formation of the precipitate. 6. Write the complete ionic equation for the formation of the gas. Use the atomic windows to answer Question 12. Oxygen atoms are red; nitrogen atoms are blue. a. b. c. d. 12. Which windows represent (1) the reactants and (2) the products for the following reaction? 2NO(g) O 2 (g) 2NO 2 (g) Standardized Test Prep 351 Chemical Reactions 351