CHAPTER 8 HOMEWORK 8-1 (pp. 241 245) Define. 1. reactants 2. products 3. chemical equation 4. precipitate 5. word equation GRAPHIC ORGANIZER Complete the chart by listing three signs that suggest that a chemical reaction has taken place. Include an example of each indication. Use additional paper if necessary. Indication of Chemical Reaction Example On a separate sheet of paper, create a chart or checklist to help you remember the characteristics of a chemical equation. Use a form that makes sense to you and include examples. 1. In a chemical equation, a coefficient indicates a. the exact amount of substance used as products in a chemical equation. b. the relative number of moles of substance in a reaction. c. the correct formulas of the reactants and products. d. that a precipitate has formed. 2. Which coefficients would you add to balance the chemical equation Fe + O 2 Fe 2 O 3? a. 2, 3, 1 b. 3, 2, 1 c. 4, 3, 2 d. The equation is already balanced.
CHAPTER 8 HOMEWORK 8-2 (pp. 245 248) Define. 1. catalyst 2. reversible reaction Write the symbol that corresponds to each explanation. Explanation A reaction is carried out at 20ºC. Indicator of result of a reaction Indicator of a gaseous reactant Indicator of a solid precipitate A reactant or product in the solid state Indicates a reversible reaction Indicates that reactants are heated Symbol SKILL BUILDER Write balanced chemical equations for each of these chemical reactions. Methane and oxygen react to form hydrogen and carbon dioxide. Methane and chlorine react to form carbon tetrachloride and hydrochloric acid. Hydrochloric acid and barium hydroxide react to form barium chloride and water. Silicon oxide and hydrofluoric acid react to form silicon tetrafluoride and water. 1. Which sentence is the correct translation for the equation 4Fe(s) + 3O 2 (g) 2Fe 2 O 3 (s)? a. Iron and dioxygen react to form bi-iron trioxide. b. Solid iron and gaseous oxygen react to form solid iron(iii) oxide. c. Solid iron and solid oxygen react to form iron trioxide. d. Iron and oxygen react to form gaseous iron(iii) oxide. 2. Chemical equations must be balanced in order to satisfy a. the law of inverse proportions. b. the Pauli exclusion principle. c. the law of conservation of energy. d. the law of conservation of mass.
CHAPTER 8 HOMEWORK 8-3 (pp. 248 250) Complete each sentence. 1. A chemical equation is like an algebraic equation because they both. 2. The coefficients of a chemical reaction indicate. 3. A chemical equation shows the smallest numbers of atoms, molecules, or ions that will satisfy 4. The relative masses of the reactants and products of a chemical reaction can be determined from 5. A chemical equation does not give information about SKILL BUILDER Calculate the relative masses of the reactants and products in each chemical reaction. Show your work. Use an additional sheet of paper if necessary. Zn + 2HCl ZnCl 2 + H 2 4Fe + 3O 2 2Fe 2 O 3 C 3 H 8 + 5O 2 3CO 2 + 4H 2 O 2KClO 3 2KCl + 3O 2 1. For a chemical equation to be balanced, a. only the number of atoms must be the same in the reactants and the products. b. the coefficients of the products must be greater than the coefficients of the reactants. c. the number and types of atoms must be the same in the products and reactants. d. the number of moles of reactant must be equal to the number of moles of product. 2. According to the reaction 2Fe 2 O 3 + 3C 4Fe + 3CO 2, how many grams of carbon dioxide are produced according to calculations of relative masses? a. 36.03 g b. 44.01 g c. 84.03 g d. 132.03 g
CHAPTER 8 HOMEWORK 8-4 (pp. 250 255) Select the term in Column B that matches the expression in Column A. Column A Column B 1. balanced chemical equation a. 2H 2 + O 2 2H 2 O 2. aqueous hydrochloric acid b. (l) 3. unbalanced formula equation c. hydrogen and oxygen yield water 4. liquid state d. 5. yield e. HCl (aq) 6. reversible reaction f. 7. word equation g. H 2 + O 2 H 2 O GRAPHIC ORGANIZER On a separate sheet of paper, create a flow chart that shows the steps in balancing a chemical equation. Include at least five steps. Illustrate how to perform the steps by writing a balanced chemical equation that shows the following: Potassium chloride and lead nitrate react to form potassium nitrate and lead chloride. 1. Which shows a correctly balanced chemical equation? a. Ca + O 2CaO b. MgO + HCl MgCl + OH c. H 2 SO 4 + NaOH Na 2 SO 4 + H 2 O d. NH 4 NO 2 N 2 H 3 + H 2 O 2. Which shows a correctly balanced chemical equation? a. 2Mg + O 2 2MgO b. C 3 H 8 + O 2 CO 2 + H 2 O c. Ca 3 PO 4 + H 2 SO 4 CaSO 4 + H 3 PO 4 d. K + H 2 + OH KOH + H 2
CHAPTER 8 HOMEWORK 8-5 (pp. 256 258) AND SKILL BUILDER Answer each question. 1. What is another name for a synthesis reaction? What happens in a synthesis reaction? 2. How is an oxide formed? 3. What are active metals? What happens when oxides of active metals react with water? SKILL BUILDER Circle the equations that show synthesis reactions. a. 2Na + Cl 2 2NaCl b. Zn + 2HCl ZnCl 2 + H 2 c. Br + LiI LiBr + I d. 4Fe + 3O 2 2Fe 2 O 3 e. 2H 2 O 2H 2 + O 2 f. Ca + O CaO g. Mg + O 2 MgO h. H 2 CO 3 CO 2 + H 2 O 1. In the equation 2Mg(s) + O 2 (g) 2MgO(s), MgO is a. an oxide. b. a reactant. c. a precipitate. d. an oxyacid. 2. Which is an example of a synthesis reaction? a. Water becomes ice when it is subjected to temperatures below 32ºF. b. A flame ignites when a stove s burner is turned on. c. Liquid coffee is produced when water drips through ground coffee at high temperatures. d. Iron turns to rust when it is exposed to oxygen.
CHAPTER 8 HOMEWORK 8-6 (pp. 258 260) AND SKILL BUILDER Define. 1. decomposition reaction 2. electrolysis 3. binary compound Complete the sentences. 4. The general equation that represents a decomposition reaction is. 5. A binary compound decomposes into 6. Joseph Priestley s contribution to chemistry was 7. When a metal chlorate is heated, it decomposes to produce. 8. When a metal carbonate is heated, it produces. GRAPHIC ORGANIZER On a separate sheet of paper, create a chart to record the different types of reactions. Include synthesis, decomposition, single-replacement, double-replacement, and combustion reactions. For each, write a general equation and a specific reaction. (You will find out about single-replacement, double-replacement, and combustion reactions later in the chapter.) Add to your chart as you continue reading. 1. Which is a correctly balanced equation that represents a decomposition reaction? a. H 2 CO 3 H 2 O + CO 2 b. C 4 H 10 O CO 2 + H 2 O c. NH 4 NO 2 NH 3 + H 2 O d. both a and c. 2. Which is the correctly balanced equation for the reaction B 10 H 18 O 2 + O 2 B 2 O 3 + H 2 O? a. B 10 H 18 O 2 + 6O 2 5B 2 O 3 + 3H 2 O b. B 10 H 18 O 2 + 11O 2 5B 2 O 3 + 9H 2 O c. 2B 10 H 18 O 2 + 6O 2 10B 2 O 3 + 8H 2 O d. The equation is already balanced.
CHAPTER 8 HOMEWORK 8-7 (pp. 261 264) Define. Then write the equation. 1. a. displacement reaction b. Write the general equations that represent displacement reactions. 2. a. double-replacement reaction b. Write the general equation that represents a double replacement reaction. 3. combustion reaction GRAPHIC ORGANIZER Create a chart on the back of this paper or on a separate sheet. Label the columns with the five types of reactions. Then classify each of the reactions below by type, writing it in the appropriate columns in the chart. Zn + 2HCl ZnCl 2 + H 2 CH 4 + 2O 2 CO 2 + 2H 2 O Mg + O 2 MgO 2 MgCO 2 + 2HCl MgCl 2 + H 2 CO 3 2KCl + Pb(NO 3 ) 2 2KNO 3 + PbCl 2 C 7 H 16 + 11O 2 7CO 2 + 8H 2 O 2Al 2 O 3 4Al + 3O 2 2Na + 2H 2 O 2NaOH + H 2 1. Which type of reaction occurs when bromine and lithium iodide react to form lithium bromide and iodine? a. combustion b. decomposition c. single replacement d. none of the above 2. Which type of reaction occurs when an acid disintegrates to become a nonmetal oxide and water? a. combustion b. synthesis c. double replacement d. none of the above
CHAPTER 8 HOMEWORK 8-8 (pp. 265 267) AND SKILL BUILDER Complete each sentence. 1. An activity series is. 2. When Mg, Al, Mn, or Zn reacts with oxygen, the result is 3. When Ni reacts with acid, it 4. The metals Ag and Pt are reactive than Co and Rb. 5. Activity series are used to predict SKILL BUILDER Use the activity series shown in Table 8-3 to predict whether each of the possible reactions listed below will occur. For the reactions that will occur, write a balanced equation showing the reactants and products. Rb(s) + H 2 (g) Zn(s) + H 2 O(aq) Mg(s) + 2HCl(aq) Fe(s) + H 2 O(g) Pt(s) + H 2 O(l) Al(s) + O 2 (g) 1. Which equation is correctly balanced? a. S 8 + F 2 SF 6 b. S 8 + 4F 2 2SF 6 c. S 8 + 3F 2 8SF 6 d. S 8 + 24F 2 8SF 6 2. Which reaction would not be predicted to occur by the activity series? a. Ni + O 2 b. Au + H 2 c. Sr + H 2 O d. Pb + HCl