Chemistry 6.0 Name________________________________Chapter 8 – Chemical Equations

Chemical Equations Introduction:

Write complete equations for the following:

1. Two moles of solid sodium chloride decompose when exposed to an electric current into two moles of sodium metal and 1 mole of chlorine gas.

2. One mole of barium chloride in solution reacts with one mole of sodium sulfate in solution to produce 1 mole of solid barium sulfate and 2 moles of sodium chloride in solution.

3. Two mole of solid potassium chlorate, when heated, decompose into two moles of solid potassium chloride and 3 moles of oxygen gas.

4. One mole of solid calcium carbonate decomposes when heated into one mole of solid calcium oxide and 1 mole of carbon dioxide gas.

5. Two moles of solid aluminum hydroxide decomposes when heated into one mole of solid aluminum oxide and three moles of water vapor.

6. One mole of zinc metal when mixed with two moles of a hydrochloric acid solution react and produce one mole of zinc chloride in solution and one mole of hydrogen gas.

7. Eight moles of fluorine gas are bubbled through a solution containing eight moles of potassium sulfide and react to produce sixteen moles of potassium fluoride in solution and one mole of solid sulfur.

2Balancing Equations: Balance the following reactions. Place a “B” at the beginning of any that are

balanced as written.

8. _____ Zn + _____O2 → _____ZnO

9. _____HI → _____H2 + _____I2

10. _____B + _____F2 → _____BF3

11. _____N2 + _____H2 → _____NH3

12. _____Fe + _____H2O → _____Fe3O4 + _____H2

13. _____BaCl2 + _____H2SO4 → _____BaSO4 + _____HCl

14. _____P4 + _____O2 → _____P4O10

15. _____KClO3 → _____KCl + _____O2

16. _____C3H8 + _____O2 → _____CO2 + _____H2O

17. _____Cu + _____AgNO3 → _____Cu(NO3)2 + _____Ag

18. _____Te + _____H2O → _____TeO + _____H2

19. _____La(NO3)3 + _____NaOH → _____La(OH)3 + _____NaNO3

20. _____RhO3 → _____RhO + _____O2

21. _____Hf + _____N2 → _____Hf3N4

22. _____Ga + _____H2SO4 → _____Ga2(SO4)3 + _____H2

23. _____PdCl2 + _____HNO3 → _____Pd(NO3)2 + _____HCl

24. _____RbBr + _____AgCl → _____AgBr + _____RbCl

25. _____PaI5 → _____Pa + _____I2

326. Na + O2 → Na2O

27. H2 + O2 → H2O

28. Na2SO4 + CaCl2 → CaSO4 + NaCl

29. Al2O3 → Al + O2

30. C2H6 + O2 → CO2 + H2O

31. SO3 + H2O → H2SO4

32. SiCl4 → Si + Cl2

33. C + H2 → CH4

34. Br2 + NaI → NaBr + I2

35. Zn + HCl → ZnCl2 + H2

36. H2S + O2 → H2O + SO2

37. Ba(NO3)2 + Na2SO4 → BaSO4 + NaNO3

38. C5H12 + O2 → CO2 + H2O

39. HgO → Hg + O2

40. H2SO4 + Pb + PbO2 → PbSO4 + H2O

41. C6H12O6 + O2 → CO2 + H2O

42. Ca + H2O → Ca(OH)2 + H2

43. C6H12O6 → C2H5OH + CO2

44. HC2H3O2 + NaHCO3 → CO2 + NaC2H3O2 + H2O

45. NaCl + SO2 + H2O + O2 → Na2SO4 + HCl

46. Fe2O3 + CO → CO2 + Fe

47. Ca3(PO4)2 + C + SiO2 → CaSiO3 + CO + P4

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48. aluminum + hydrochloric acid aluminum chloride + hydrogen

49. chromium(III) hydroxide + nitric acid water + chromium(III) nitrate

50. chromium + hydrobromic acid chromium (III) bromide + hydrogen

51. krypton difluoride + water krypton + oxygen + hydrofluoric acid

52. chlorine + water hydrochloric acid + oxygen

53. CH3OH + O2 CO2 + H2O

54. Si2H6 + O2 SiO2 + H2O

55. CH3NH2 + O2 CO2 + H2O + N2

56. Na2SiO3 + HF H2SiF6 + NaF + H2O

57. NH3 + O2 NO + H2O

58. Sb2S3 + HCl H3SbCl6 + H2S

59. Al + NaOH + H2O NaAl(OH)4 + H2

60. C2H5Cl+ NaPb (C2H5)4Pb + NaCl + Pb

5Types of Reactions: Balance the following equations and indicate the type of reaction on the line

provided.

61. NaCl → Na + Cl2 _____________________

62. Na + Cl2 → NaCl _____________________

63. C2H4 + O2 → CO2 + H2O _____________________

64. H2O → H2 + O2 _____________________

65. H2 + O2 → H2O _____________________

66. C8H18 + O2 → CO2 + H2O _____________________

67. NaOH + HCl → H2O + NaCl _____________________

68. Na + HCl → H2 + NaCl _____________________

69. K + Cl2 → KCl _____________________

70. K + AgCl → Ag + KCl _____________________

71. C6H12 + O2 → CO2 + H2O _____________________

72. Ca + S8 → CaS _____________________

73. KOH + HNO3 → H2O + KNO3 _____________________

74. Al + O2 → Al2O3 _____________________

75. HgO → Hg + O2 _____________________

76. NaOH + H2SO4 → Na2SO4 + H2O _____________________

77. Fe + O2 → Fe2O3 _____________________

78. C6H8 + O2 → CO2 + H2O _____________________

79. Pb(NO3)2 + K2CrO4 → PbCrO4 + KNO3 _____________________

80. H2 + N2 → NH3 _____________________

81. C3H5(NO3)3 → CO2 + N2 + H2O + O2 _____________________

6Decomposition, Synthesis, and Combustion

82. Pt2O

83. Mg(ClO3)2

84. P2O5

85. SrO + H2O →

86. BaCO3

87. HNO3(aq)

88. C4H10 + O2 →

89. Al + O2

90. Cl2O3 + H2O →

91. Al(OH)3

92. iron(III) chlorate is heated

93. zinc oxide powder is added to water

94. pentane (C5H12) is ignited in air

95. phosphorous acid is heated

96. magnesium phosphide is exposed to an electric current

97. lithium hydroxide is heated

98. hydrogen gas is ignited in air

799. magnesium ribbon is heated in the presence of sulfur

100. scandium carbonate is heated

101. dinitrogen pentoxide gas is bubbled through water

Single Replacement

102. Zn + CuSO4 →

103. Pb + Mg(NO3)2 →

104. AgC2H3O2 + Li →

105. Cl2 + KBr →

106. HF(aq) + Ca →

107. magnesium + nitric acid →

108. sodium chloride + aluminum →

109. barium + calcium sulfate →

110. nickel(II) sulfate + lithium →

111. potassium + water →

112. silver + strontium chloride →

113. sodium fluoride + iodine →

114. rubidium + iron(III) sulfate →

115. sodium + water →

8116. fluorine + aluminum bromide →

117. phosphoric acid + calcium →

118. copper + water →

Double Replacement

119. AgCH3COO + CaSO4 →

120. Pb(NO3)2 + Na2S →

121. AgNO3 + FeCl3 →

122. H2SO4 + Ba(OH)2 →

123. Al(OH)3 + NH4Cl →

124. A solution of lead(II) chlorate is mixed with a solution of chromium(III) iodide.

125. A solution of nitric acid is added to a solution of magnesium hydroxide.

126. Solutions of copper(II) chloride and potassium carbonate are mixed.

127. Solid sodium carbonate is sprinkled on a hydrochloric acid spill.

128. Perchloric acid is neutralized by the addition of ammonium hydroxide.

Energy and Change of Enthalpy

129. Indicate the following as either exothermic or endothermic.

a) CH4 + 74.4 kJ → C + 2H2 a) ___________________

b) 1/8 S8 + O2 → SO2 b) ___________________

c) 3 C + 4 H2 → C3H8 + 104 kJ c) ___________________

d) butane + oxygen → carbon dioxide + water d) ___________________

e) CO2 → CO + ½ O2 ΔH = +238kJ e) ___________________

9130. The energy term of an exothermic reaction is added to the (right / left) side of chemical

equation because energy is (absorbed / released).

131. The ∆H of an endothermic reaction is indicated as a (+ / −) value because the enthalpy (potential energy) of the reactants is ( > / < ) than the enthalpy of the products.

132. All chemical fuels produce an (endothermic / exothermic) reaction upon ordinary combustion.

133. Baking a potato is an example of an (exothermic / endothermic ) reaction.

134. Copper and oxygen react according to the following: Cu + ½ O2 → CuO ∆H = −155kJ Rewrite this equation for 1 mole of O2 and include energy in the equation.

135. Carbon and sulfur react according to the following equation: 4C + S8 + 3511 kJ → 4CS2 Rewrite the equation for one mole of C, using the ∆H notation.

136. Draw an energy diagram for the equation given in the previous problem. Be sure to label all parts. (progress of the reaction, enthalpy or energy, ∆H, reactants, and products.

137. Using the graph below, determine:

a. The activation energy needed for the forward reaction?___________________

b. The activation energy needed for the reverse reaction? ___________________

c. ∆H for the forward reaction? Endothermic or exothermic? ___________________

d. ∆H for the reverse reaction? Endothermic or exothermic? ___________________

e. Label the activated complex on the curve.

f. Sketch what the curve might look like if a catalyst was added.

10138. Draw a potential energy diagram with the following criteria:

a. ∆Hrev = −30 kJb. Ea (forward reaction) = 70 kJc. Activated Complex = 90 kJ

139. Based on your diagram, determine:

a. ∆Hfor _____________________

b. Ea (reverse) _________________

c. Enthalpy of reactants__________________

d. Enthalpy of products_________________

Bond Energy

140. Given:

a. Identify the type and number of bonds broken in this reaction and determine the total amount of energy required to break them.

b. Identify the type and number of bonds formed in this reaction and determine the total amount of energy released when they are formed.

c. Calculate the enthalpy change for the entire reaction.

d. Is this reaction endothermic or exothermic?

e. Write a thermochemical equation for the reaction.

f. Draw and label a potential energy diagram for the reaction.

11141. Using bond energies, calculate the enthalpy change for the following reactions:

a.

b.

c.

d.

12Ionic Equations and Dissociation Reactions

1. Write appropriate ionization equations or dissociation equations to represent what happens when each of the following chemicals are mixed with water:

a. HNO3(aq)

b. H2SO4(aq)

c. LiOH

d. Ba(OH)2

e. Na2SO4

2. Write molecular, ionic and net ionic equations for each of the following:

a. Solutions of potassium hydroxide and nitric acid are mixed.

b. Solutions of barium chloride and sodium sulfate are mixed.

c. Solid calcium oxide is added to a hydrochloric acid solution

d. Solutions of lithium acetate and copper(II) nitrate are mixed.

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e. Solutions of iron(III) bromide and ammonium carbonate are mixed

f. A piece of zinc metal is added to a solution of copper(II) sulfate.

g. Solid lead(II) nitrate crystals are sprinkled into a solution of rubidium iodide.

h. A piece of aluminum metal is added to a solution of silver nitrate.

14Review (Identify reaction type before writing the equation)

142. calcium metal is added to a solution of nitric acid.

143. solutions of copper(II) nitrate and sodium hydroxide are mixed.

144. scandium carbonate is heated

145. nitrous acid is heated

146. zinc + magnesium carbonate →

147. dichlorine monoxide + water →

148. calcium carbonate + perchloric acid →

149. strontium chlorate is heated

150. lead(IV) sulfide is exposed to an electric current

151. the combustion of octane (C8H18)

152. silver oxide + water →

153. dichromic acid + ammonium hydroxide →

154. barium metal is dropped in water

155. copper(II) hydroxide is heated

156. lithium + sulfur →

157. bromine + iron(III) iodide →

158. solutions of sodium phosphate and calcium bromide are mixed.

159. barium metal is added to a solution of chlorous acid.

15160. chloric acid is heated

161. aluminum metal is added to a solution of sodium chlorate

162. dinitrogen pentoxide gas is bubbled through water

163. lithium carbonate is heated

164. ammonium carbonate powder is sprinkled on a hydrochloric acid spill

165. iron(III) phosphide is exposed to an electric current

166. hexane (C6H14) is ignited

167. tin(II) oxide is added to water

168. strontium hydroxide is combined with acetic acid

169. tin(IV) hydroxide is heated

170. a piece of silver metal is held in a Bunsen burner flame

171. lead(II) sulfide is heated in a fluorine environment

172. calcium hydroxide powder is added to an ammonium nitrate solution

173. A hydrocarbon compound is found to be 85.71% carbon and 14.29% hydrogen by mass. When vaporized at 35ºC, 0.136 g of the compound occupies a volume of 45.0 mL and exerts a pressure of 691 torr. Write a balanced equation for the combustion of this compound.

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174. Given:

a. Write a balanced molecular equation in ΔH notation.

b. Is the reaction endothermic or exothermic?

c. Which has a higher enthalpy, the reactants or the products?

d. Would the temperature of the surroundings increase or decrease?

175. For each of the following, write complete and balanced molecular, ionic and net ionic equations.

a. Solutions of lead(II) nitrate and potassium iodide are mixed.

b. Solutions of hydrochloric acid and silver nitrate are mixed.

c. Solutions of sodium hydroxide and iron (III) nitrate are mixed.

17Cumulative Review Questions

176. For 2607000 give the following:a) Number written in scientific notation _________________________

b) Significant figures _________________________

c) Rounded to 3 significant figures _________________________

177. Convert 23.6 hectograms to milligrams

178. A copper cube with a mass of 58.60 g is placed into a water-filled graduated cylinder. The water in the cylinder rises from 26.5 mL to 33.1 mL. Determine the density of the copper?

179. List 3 physical properties and 3 chemical properties of water.

180. Complete the following chart

Homogeneous or Heterogeneous

Element, Compound, Mixture, Solution

rubbing alcohol

calcium oxide

gasoline

181. Write nuclear equations for:

a) Alpha emission of radon-222

b) Electron capture by nitrogen-15

c) Neutron bombardment of oxygen-16

182. What is the mass and charge of 5.26 x 1024 electrons?

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183. A 2.65 gram sample of cobalt-55, with a half-life of 17.5 hours undergoes decay for 6.56 days. What mass of cobalt-55 remains at this point?

184. An element consists of 1.40% of an isotope with mass 203.973 amu, 24.10% of an isotope with mass 205.9745 amu, 22.10% of an isotope with mass 206.9759 amu, and 52.40% of an isotope with mass 207.9766 amu. Calculate the average atomic mass and identify the element.

185. Where appropriate, write formulas or names for each of the following:

a. ammonium sulfate ___________ f) H3AsO4(aq)_________________________

b. dinitrogen monoxide ___________ g) FeSO3 _________________________

c. phosphorous acid ___________ h) CuSO4•5H2O ______________________

d. lead(IV) oxalate ___________ i) BF3 _________________________

e. aluminum nitrite ___________ j) Cr(OH)3 _________________________

186. Determine the mass, in grams, of 4.22 x 1024 formula units of copper(I) sulfide.

187. What is the total number of electrons in 0.915 moles of nitrogen atoms?