Name: Period: CHEMISTRY I HONORS SEMESTER 2 EXAM REVIEW Unit 9: Stoichiometry How does the amount of each reactant present at the start of a chemical reaction determine how much product forms? How are balanced chemical equations used when solving stoichiometric problems? What causes chemical reactions to stop? What is a limiting reagent What is the percent yield of a chemical reaction? reactant product stoichiometry mole ratio chemical reaction limiting reactant excess reactant theoretical yield actual yield percent yield 1. Differentiate between the significance of the coefficients in a balanced chemical equation and the significance of the subscripts in a chemical formula. 2. State the Law of Conservation of Mass and explain its relationship to stoichiometry. 3. One disadvantage of burning propane (C 3H 8) is that carbon dioxide is one of the products. The released CO 2 increases the growing concentration of CO 2 in the atmosphere. How many moles of carbon dioxide are produced when 10.0 moles of propane are burned in excess oxygen on a gas grill? C 3H 8 + O 2 CO 2 + H 2O 4. Water decomposes to produce hydrogen gas and oxygen gas. How many grams of water would be required to produce 10.0 moles of hydrogen gas? H 2O H 2 + O 2 5. If 25.0 grams of carbon dioxide are used in photosynthesis how many moles of glucose (C 6H 12O 6) could be produced according to the following equation: 6CO 2 + 6H 2O C 6H 12O 6 + 6O 2 6. One series of reactions that inflates air bags in automobiles is the decomposition of sodium azide (NaN 3). Determine the amount in grams of N 2 produced if 100.0 g of NaN 3 is decomposed using the following unbalanced equation: NaN 3 Na + N 2 1 L. Tait
7. Nitrogen gas reacts with hydrogen gas to produce ammonia: N 2 + H 2 NH 3 If 100.0 g of nitrogen gas reacts with 20.0 g of hydrogen gas what mass of ammonia will be produced? 8. Iron reacts with oxygen to form Iron (III) oxide. 4Fe + 3O 2 2Fe 2O 3. a) If 200.0 g of iron reacts, what is the theoretical yield of iron (III) oxide? b) If the actual yield is 205.4 g, what is the percent yield of the reaction? 2
Unit10: States of Matter What is the relationship between temperature and kinetic energy? How are degrees Celsius converting into Kelvin? What are some examples of chemical properties? Physical properties? What are some examples of some chemical changes? Physical changes? How do intermolecular forces determine a substances state? How do intermolecular forces determine the range of motion of particles in solids and liquids? How do intermolecular forces determine the range of motion of particles in gases? How are plasmas different from gases? What makes matter change phase? How does a phase change reach dynamic equilibrium? Polar covalent bond dispersion force dipole-dipole force hydrogen bond viscosity surface tension melting point vaporization evaporation vapor pressure boiling point freezing point condensation deposition 9. Place a check in the box if the description applies to solids, liquids and/or gases. Each characteristic may apply to 1, 2 or all 3 states: Highly compressible Fluid Takes the shape of its container Fills the volume of its container Particles are far apart from one another Molecules are moving Solids Liquids Gases 10. Fill in the chart below with the appropriate phase change: (a thru f) a. b. c. Gases Liquids Solids d. e. f. 11. Which of the above (a thru f) are exothermic? Which of the above (a thru f) are endothermic? 12. Water boils when the pressure is equal to the pressure. 13. How are temperature and the kinetic energy of molecules related? 14. What is plasma? 3
15. Put hydrogen bonds, dispersion forces and dipole-dipole forces in order of how strong they are and give an example of each type of attraction. 16. Why do polar compounds tend to have higher melting boiling points than nonpolar compounds? 4
Unit 11: Gases What is absolute zero? How does the kinetic molecular theory explain the behavior of gases? How are pressure units converted? What is Daltons Law of partial pressures? Why are they called Laws and not theories? How are temperature, pressure and volume related? What is Standard temperature and pressure? How can the volume, pressure or temperature of a gas be calculated? Can the amount of moles of a gas be related to the pressure, volume and temperature of the sample? Do gases always follow the idea gas law? How can balanced equations be used to calculate the volume of gases formed in chemical reactions? Kinetic molecular theory elastic collision temperature pressure absolute zero combined gas law molar volume ideal gas law ideal gas constant 17. List the five main assumptions of the kinetic-molecular theory. Spacing and particle size Attraction/repulsion Movement Collision type Temperature 18. What causes the pressure of a gas inside of a container? 19. What is the combined gas law? 20. What are Standard Temperature and Pressure? 21. If the temperature of a weather balloon is increased how does the volume of the balloon change? 22. A gas at 110 kpa and 30.0 o C fills a flexible container with an initial volume of 2.00 L. If the temperature is raised to 80.0 o C and the pressure is increased to 440 kpa, what will be the new volume? 23. What is the volume of a 125.0 ml of a gas at 1.50 atm and 100.0 o C at STP? 24. What are the values (with units) for R,the ideal gas constant? 25. Calculate the number of moles of gas contained in a 3.0 L vessel at 300.K with a pressure of 1.50 atm. 5
26. Hydrogen gas reacts with oxygen gas to produce water at STP. How many liters of hydrogen gas are required to produce 25.0 grams of water? H 2 + O 2 H 2O 27. John puts 1250 PSI of Oxygen, 780 PSI of Nitrogen and 550 PSI if Helium in a SCUBA tank. What is the total pressure? 28. Under what conditions do gases follow the Ideal gas Law? 6
Unit 12: Solutions What factors affect the formation of solutions? How is the concentration of a solution calculated using molarity? How does a solution become saturated or supersaturated? What factors affect the solubility of gases and solids in liquids? What's the difference between strong, weak, and nonelectrolytes? What properties of solutions are colligative properties? How does an increase in vapor pressure affect the colligative properties of a solution? How would an equation be written for the dissociation of ionic solutes in water? Why does oil not dissolve in water according to the factors that affect solubility? How does an increase in temperature and pressure of a solution affect the solubility of the solute? How does polarity of the solute and solvent affect the solubility of a solution? Compare, contrast, and provide examples of suspensions, colloids, and solutions similar and different. What does a solubility curve represent? solution soluble insoluble solvation (hydration) like dissolves like solubility saturated solution unsaturated solution supersaturated solution concentration molarity colligative properties suspension colloids electrolyte nonelectrolyte 29. In general, what two classes of materials will dissolve in water? 30. Which is more concentrated, 10.0 grams of sugar in 100.0 ml of water or 10.0 grams of sugar in 125.0 ml of water? Why? 31. Solubility of solids and gases: Factors that affect solvation rate of SOLIDS in liquids: The rate of the solvation...(circle your choice) Temperature of the solution increases Increases Decreases The mixture is stirred Increases Decreases The solid is broken into smaller pieces Increases Decreases Factors that affect solubility of GAS in a liquid: The solubility of the gas in the liquid (Circle your choice) Temperature of the solution increases Increases Decreases The pressure over the gas is decreased Increases Decreases The pressure over the gas is increased Increases Decreases 32. If a crystal of solute was added to each of the following types of solutions, what would happen? unsaturated saturated supersaturated 33. What three classes of compounds are electrolytes? 34. Give two examples of nonelectrolytes. 7
35. According to Reference Table G, which solution is saturated at 30 C? (circle one) (a) 12 grams of KClO 3 in 100 grams of water (b) 12 grams of KClO3 in 200 grams of water (c) 30 grams of NaCl in 100 grams of water (d) 30 grams of NaCl in 200 grams of water 36. According to Reference Table G, the solubility of which compound is least affected by a change in temperature? 37. Fill out the chart to show how the addition of a solute to a solvent will affect the melting point (MP) and the boiling point (BP) of the solution, and why these temperatures are affected. Condition Required to change the phase of the pure liquid Affect of adding solute Boiling Point pressure is equal to pressure Boiling Point is because the number of solvent particles at the surface is reduced thereby lowering the vapor pressure requiring a/an in temperature to achieve atmospheric pressure. Melting point Kinetic energy of particles overcomes attractive forces present in the solid state. Melting point is because solute particles disruptinter-particle attractive forces allowing melting to occur at a temperature. 38. A 100.5 ml intravenous (IV) solution contains 5.10 g glucose (C 6H 12O 6). What is the molarity of this solution? 39. How many grams of sodium hydroxide are required to prepare 500.0 ml of a 2.00 M solution? 8
Unit 13: Thermochemistry& Reaction Rates What are some types of renewable and nonrenewable energy resources? What is energy and how is it measured? What is the difference between temperature and heat energy? What is an endothermic process and what is the sign for ΔH for the process? What is an exothermic process and what is the sign for ΔH for the process? What is the SI unit for energy? How are system, surroundings, and universe defined in thermochemistry? How is the Law of Conservation of Energy applied using calorimetry? What is specific heat capacity? Why does it take more heat to change the temperature of water compared to metals? What factors impact the rate of a chemical reaction, and how is the rate changed for each factor? How are endothermic and exothermic reactions represented in an energy diagram? What is a catalyst? How does a catalyst work? What is a reversible reaction? What do molecular clocks have to do with reaction rates? thermochemistry heat exothermic Collision Theory absolute zero specific heat renewable energy Reaction Rate calorie calorimeter source Concentration joule surroundings nonrenewable energy Surface Area energy system source Catalyst law of conservation of universe chemical potential Molecular Clocks energy endothermic energy 40. What is the derived unit for specific heat? 41. Select the word in the parenthesis that makes the statement true: An object with a higher specific heat requires (more / less) heat to raise its temperature. 42. How many kj are equal to 500.0 calories? 43. What is the SI unit for energy/heat? 44. Select the word in the parenthesis that makes the statement true: An (endothermic/exothermic) reaction releases heat so the container would feel (warm/cold) while an (endothermic/exothermic) reaction absorbs heat from the surroundings so the container would feel (warm/cold). 45. Select all the phrases in the parenthesis that make the statement true: The flat lines on a heating curve represent (a temperature change/ a constant temperature/ a change of state). 46. Select all the phrases in the parenthesis that make the statement true: The sloped lines on a heating curve represent (a temperature change/ a constant temperature/ a change of state). 47. Select all the phrases in the parenthesis that make the statement true: It takes longer for substances to (melt / boil) because the heat of vaporization is (higher / lower) than the heat fusion. 48. When a hot object is put in cooler water, what will happen to the temperature of the object? To the temperature of the water? 49. Convert 25 o C to Kelvin. Convert 25K to o C. 9
50. Why are there no negative temperatures in the Kelvin system? 51. Which statement describes characteristics of an endothermic reaction? (check one) The sign of H is positive, and the products have less potential energy than the reactants. The sign of H is positive, and the products have more potential energy than the reactants. The sign of H is negative, and the products have less potential energy than the reactants. The sign of H is negative, and the products have more potential energy than the reactants. 52. Select all the phrases in the parenthesis that make the statement true: The average kinetic energy of a substance s molecules (increases / decreases) as it cools from 273K to 263K. 53. Select all the phrases in the parenthesis that make the statement true: Solid X is placed in contact with solid Y. Heat will flow spontaneously from X to Y when (X is 20 C and Y is 20 C/ X is 10 C and Y is 5 C/ X is -25 C and Y is -10 C/ X is 25 C and Y is 30 C). 54. What is the total number of joules of heat energy absorbed by 15 grams of water when it is heated from 30.0 C to 40.0 C?The specific heat of water is 4.184 J/g C. 55. The heat of fusion of water is 6.01 kilojoules per mole. What is the total number of kilojoules of heat that must be absorbed by a 15.0 gram sample to change the compound from a solid to a liquid at 0 C? 56. Salt A and salt B were dissolved separately in 100 ml beakers of water. The water temperatures were measured and recorded as shown in the table below: initial water temp. final water temp. Salt A: 25.1 C 30.2 C Salt B: 25.1 C 20.0 C 57. How does each factor affect the rate of a chemical reaction? Factors that affect reaction rate: Select all the phrases in the parenthesis that make the statement true: The dissolving of (only salt A was endothermic/ only salt B was exothermic/ both salt A and salt B were endothermic/ salt A was exothermic and the dissolving of salt B was endothermic). The rate of the reaction. (Circle your choice) Concentration of the reactants increases Increases Decreases Concentration of the reactants decreases Increases Decreases Temperature increases Increases Decreases Temperature decreases Increases Decreases An inhibitor is added Increases Decreases A catalyst is added Increases Decreases The pressure of a reactant gas is increased Increases Decreases The pressure of a reactant gas is decreased Increases Decreases 58. Draw and label the following reaction diagrams. Be sure to label the activation energy ( Ea) and the change in heat ( H) on each diagram: Exothermic Exothermic with a Catalyst Endothermic 59. Fill in the missing terms: A speeds up a reaction by lowering the 10
Unit 14: Acids and Bases What is the definition of an acid? Base? What are the properties of acids? Bases? What is the purpose of an indicator? Give an example. What are some common acids and bases? What is ph? What is the ph range of an acid? Of a base? Of a neutral? How can you identify a neutralization reaction? How does a scientist use a titration experiment to calculate the concentration of an unknown solution? What are the causes and environmental effects of acid rain? acidic solution Arrhenius acid Arrhenius base basic solution Bronsted-Lowry acid Bronsted-Lowry base conjugate acid conjugate base conjugate acid-base pair strong acid weak acid strong base weak base ion product constant for water ph poh acid-base indicator buffer end point equivalence point neutralization reaction salt titration monoprotic diprotic acid rain 60. List at least 5 properties of acid and bases in the table: Acid Base 61. Acids react with many metals. What will be the second product of the reaction below? HCl + Mg ---> MgCl 2 (aq) + (g) 62. Which of these ph numbers indicates the highest level of acidity? (a) 5 (b) 8 (c) 10 (d) 12 63. A solution with a ph of 2.0 has a hydrogen ion concentration ten times greater than a solution with a ph of: (a) 1.0 (b) 3.0 (c) 0.20 (d) 20 64. Compare and contrast the Arrhenius and Bronsted-Lowry: Arrhenius Bronsted-Lowry 65. Differentiate between strong and weak acids and bases (i.e. what makes an acid strong?) 11
66. Conjugate acid/base pairs - Using the equation below, label the: acid, base, conjugate acid, conjugate base 67. [H+], [OH-], ph, poh Fill in the chart below: NH 3 + H 2O -->NH 4 + + OH - [H 3O + ] [OH-] ph poh acid/base 1.0 X 10-3 M 2.0 X 10-3 M 5.2 12.2 68. Predict the products for this neutralization reaction: HCl + NaOH --> + 69. The data collected from a laboratory titration are used to calculate the (chose one) (1) rate of a chemical reaction (3) concentration of a solution (2) heat of a chemical reaction (4) boiling point of a solution 70. A student completes a titration by adding 12.0 milliliters of NaOH(aq) of unknown concentration to 16.0 milliliters of 0.15M HCl(aq). What is the molar concentration of the NaOH(aq)? 71. Which compound is an Arrhenius acid? (1) H 2SO 4 (2) KCl (3) NaOH (4) NH 3 72. According to one acid-base theory, water acts as an acid when an H 2O molecule (1) accepts an H + (2) donates an H + (3) accepts an H - (4) donates an H - 73. Given the reaction: HCl(aq) + LiOH(aq) HOH(l) + LiCl(aq) The reaction is best described as: (circle one) (1) neutralization (2) synthesis (3) decomposition (4) oxidation-reduction 74. What are some possible sources of the acids in the atmosphere that contribute to acid rain? 12
Unit 15: Redox What types of reactions are also classified as redox reactions? What happens during oxidation and reduction? How are oxidation numbers assigned? How are half-reactions classified as oxidation or reduction? Redox Oxidation Reduction Oxidizing Agent Reducing Agent 75. What happens during oxidation? 76. What happens during reduction? 77. List several common redox reactions: 78. Half reactions: Write the correct half reaction in the space provided. Br + 1 e - Br Mg Mg +2 + 2 e - a. Oxidation Half reaction b. Reduction Half reaction c. Balance the equation. 79. Show the oxidation number of each element: K (s) + Br 2(g) KBr (s) a. Which substance is oxidized? b. Which substance is reduced? c. What is the oxidizing agent? d. What is the reducing agent? e. Balance the equation. 13
Unit 16: Nuclear Chemistry What happens when an unstable nucleus decays? How is the structure of atoms altered during fission and fusion? How are nuclear reactions classified and balanced? What is the difference between a chemical reaction and a nuclear reaction? How does nuclear chemistry explain the natural world and affect your life? (fission and fusion in nature, half-life in fossil dating and molecular clocks and tumor location, nuclear reactions in fire detectors, cancer treatment, and power production) What are the impacts on the environment from nuclear production? How is a graph used to determine the half-life of a radioactive isotope or how much radioisotope will be present in a sample after a given time period? Fission Fusion Radioactive Decay Radioactive isotope (Radioisotope) Alpha radiation Beta radiation Gamma radiation Half-life Radioisotope tracer Exponential decay 80. Compare and contrast alpha, beta and gamma radiation: Attribute Alpha radiation Beta radiation Gamma radiation Symbols Mass Charge Penetrating ability 81. Balance the following nuclear reactions: a. 43 99 Tc + 1 0 e 239 4 b. 94Pu 2He + 239 239 c. 93Np 94Pu + 42 d. 19K 1 0 e + e. H 1 1 + H 1 3 82. In the nucleus, why don t the positive protons fly apart from electrostatic repulsion? 83. Compare radioactive decay, nuclear fission and nuclear fusion: Comparison Category Radioactive decay Nuclear fission Nuclear fusion Define Natural occurrences Technological uses 15
84. What are the advantages and disadvantages of using nuclear power plants to generate electricity? Advantages Disadvantages 85. Compare and contrast nuclear reactions and chemical reactions: Comparison Category Nuclear reactions Chemical reactions Fundamental Forces Responsible Subatomic particles affected Relative amount of energy released Current applications as an energy source Future applications as energy source 86. Interpret the graph to answer the questions: a. What is the initial mass? b. What is the half-life? c. What mass remains after 3.0 half-lives? d. What mass remains after 10 half-lives? e. After how many half-lives will 200. pounds remain? (show calculation) 16