HEATING CURVE OF UNKNOWN SUBSTANCE

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1 SPRING 2018 FINAL EXAM REVIEW STUDY GUIDE GENERAL CHEMISTRY 55 MULTIPLE CHOICE QUESTIONS STUDENTS CAN USE A CALCULATOR & TEACHER PROVIDED PERIODIC TABLE UNIT 3: THERMOCHEMISTRY Vocabulary & Concepts 1. Boiling point- 2. Melting point- 3. Solid- 4. Liquid- 5. Gas 6. Kinetic energy 7. Potential energy 8. Endothermic 9. Exothermic- 10. Law of conservation of energy Temperature 12. Heat- 13. Heat of reaction (ΔH) 14. Calorimeter 15. Insulator 16. Conductor 17. Potential Energy Diagram Students should be able to analyze and interpret heating curve graphs -Label the 3 phases, label the melting point and boiling point -Identifying changes or constants in kinetic energy or potential energy -Define and identify exothermic and endothermic changes and relate to heating curve 60 HEATING CURVE OF UNKNOWN SUBSTANCE TEMPERATURE ( C) TIME (minutes) 1

2 Students should be able to use the specific heat equation q = mcδt -To solve for any variable -Use specific heat to identify unknown metal -Relate specific heat to temperature change and conductive properties VARIABLE MEASUREMENT UNIT q m c ΔT T i SPECIFIC HEAT WATER 4.18 J /(g C) SAND 0.8 J/(g C) IRON 0.46 J/(g C) SILVER 0.24 J/(g C) BERYLLIUM 1.83 J/(g C) COPPER 0.38 J/(g C) COBALT 0.42 J/(g C) MAGNESIUM 1.0 J/(g C) NICKEL 0.50 J/(g C) T f Substance Specific heat Rate of Temperature change Conductor Insulator Students should be able to differentiate temperature and heat. Definition Example Temperature Heat 2

3 Practice Test Questions 18. What is the melting point of SUBSTANCE X? 19. What is the boiling point of SUBSTANCE X? 20. What phase of matter is the region labeled A? 21. What phase of matter is the region labeled E? 22. Which regions of the graph does both a solid and liquid exist simultaneously? 23. Which region of the graph is potential energy changing? 24. Identify as an endothermic or exothermic change: a. Solid melting into a liquid b. Gas condensing into a liquid c. Liquid solidifying into a solid 25. Which of the substances would change temperature quickly? 26. What kind of substances are best to construct a calorimeter? 27. Calculate the quantity of heat needed to heat a gram Sample of magnesium from 32 C to 85 C? SUBSTANCE SPECIFIC HEAT WATER 4.18 J /(g C) SAND 0.8 J/(g C) IRON 0.46 J/(g C) SILVER 0.24 J/(g C) BERYLLIUM 1.83 J/(g C) COPPER 0.38 J/(g C) COBALT 0.42 J/(g C) MAGNESIUM 1.0 J/(g C) NICKEL 0.50 J/(g C) 28. Calculate the change in temperature of a 5.0 gram sample of beryllium that loses 1800 Joules of heat energy? 3

4 29. A 25 gram substance changes temperature from 15 C to 55 C. Identify the substance if it absorbs 240 Joules of heat energy. 30. Identify the graph as exothermic or endothermic. 31. Would the graph have a + ΔH or ΔH? UNIT 4: REACTION RATES AND EQUILIBIRIUM Vocabulary & Concepts 32. Solvent 33. Solute- 34. Concentration 35. Molarity 36. Molality 37. Freezing point depression 38. Boiling point elevation Saturated 40. Unsaturated Supersaturated Catalyst 43. Activation energy 44. Equilibrium 45. Temperature 46. Pressure 47. LeChatelier s principle Students should be able to calculate molarity and molality. Students should be able to calculate freezing point depression and boiling point elevation using colligative property equations. Students should be able to interpret solubility curves. Students should be able to describe how a catalyst affects a chemical reaction. Students should know the characteristics of endothermic and exothermic reactions. Students should be able to convert between energy and mass using balanced equations. Students should be able to apply Lechatelier s Principle to changes made to a chemical reaction at equilibrium. Definition ΔH Example Reaction Potential Energy Diagram Exothermic Endothermic 4

5 Practice Test Questions 48. What mass of KNO 3 will dissolve at 62 C? 49. At what temperature will 8 grams of KClO 3 dissolve? 50. Which compound is least soluble at 40 C? 51. How much NH 3 would saturate 100g of H 2O at 20 C? g NaNO 3 dissolves in 100g of H 2O at 40 C, is this solution supersaturated or unsaturated? 53. What is the molarity of a solution containing 8.6 moles NaCl dissolved in 2.6 L of H 2O? 54. What is the molality of a solution containing 6.88 moles C 6H 12O 6 per 1.2 kg of solvent. 55. A copper chloride solution is made from dissolving grams CuCl 2 into 0.19 L of water. What is the molarity of the solution? 56. Calculate the freezing point of g glucose in 250g of water. Solvent K f C/m K b C/m f.p. C b.p. C Water Acetic acid Calculate the boiling point of a solution made from dissolving grams C 6H 12O 6 into 1.2 kg of acetic acid. Label as true/false 58. Endothermic reactions absorb energy. 59. A catalyst will lower the activation energy of a chemical reaction. 60. The ΔH of exothermic reactions is positive. 61. A catalyst will cause a chemical reaction rate to increase. 62. Energy flows from a substance of high temperature to low temperature. 5

6 63. What is the ΔH of this reaction? Ca(OH) 2 (s) + CO 2(g) H 2O (g) + CaCO 3 (s) kj 64. Consider the reaction: C 6H 12O O 2 6 CO H 2O ΔH = KJ What mass of oxygen will be used to produce 3000 kj of energy? 65. Consider the reaction: HCN (g) + 2 H 2(g) CH 3NH 2(g) ΔH = -138 kj/mole What amount of energy is released when 25 grams of H 2 is consumed? 66. Consider the reaction: 2 C 2H 6 (g) + 7 O 2 (g) 4 CO 2 (g) + 6 H 2O (g) H = -808 KJ/mole If grams of oxygen gas was reacted, how much energy will be released to the surroundings? 67. Given the following reaction at equilibrium: 12.6 kcal + H 2(g) +I 2(g) 2 HI(g) Which way will the equilibrium shift when the following changes are made? a) Increasing temperature b) Decreasing temperature c) Increasing pressure d) Decreasing pressure e) Increasing H 2 concentration f) Increasing I 2 concentration g) Increasing HI concentration h) Decreasing HI concentration 68. Consider the following reaction: N 2(g) + 3 H 2(g) 2NH 3(g) kcal What changes will increase the amount of NH 3 made? UNIT 5: NUCLEAR CHEMISTRY Vocabulary & Concepts: 69. Alpha 70. Beta 71. Gamma 72. Half-life 73. Radioactivity 74. Fission- 75. Fusion 76. Transmutation 77. Solar radiation 78. Electromagnetic spectrum 79. Wavelength 80. White dwarf 81. Super giant- 82. Red giant- 83. Supernova 84. Black hole 85. Big bang theory Telescope 6

7 Students should be able to compare/contrast nuclear change, chemical change and physical change. Type of change Description Example Reaction Temperature Changes 241 Students should be able to interpret proper nuclear notation 95 Students should be able to identify radioactive elements Above which atomic number are all elements radioactive? Students should be able to balance a nuclear equation including identifying the missing component. Students should be able to compare/contrast fission and fusion. Type of nuclear change Define Sample Reaction Used for FISSION FUSION Students should be able to compare/contrast the types of radioactivity: ALPHA, BETA, GAMMA Type of particle Symbol Size ALPHA Can be stopped by? (penetrative power) Example reaction BETA GAMMA Students should be able to perform half-life calculation Students should be able to describe the Big Bang Theory 7

8 Students should be able to describe the nuclear processes occurring in the sun and how solar radiation affects Earth. Students should be able to describe the electromagnetic spectrum and what it s used for. Students should be able to list the stages in the star cycle and relate to our sun. Practice Test Questions Label the following statements as properties of: Nuclear change, chemical change, or physical change 87. Temperature change of 1,000 C 88. A new element is formed 89. Same substance on reactant and product side of equation, just a different phase of matter 90. Temperature change of 100 C 91. Label the atomic number and the atomic mass for: Balance the following nuclear reactions and write in the missing component. a b c d Which of the following isotopes are radioactive? (circle all that apply) Cl U Ra Sm Sb Bk 8

9 94. Rank alpha, beta, gamma by increasing size. 95. Rank alpha, beta, gamma by decreasing penetrative power. 96. Identify as alpha, beta, or gamma decay: a b γ c d Identify as fission or fusion: a) n b) c) d) n e) f) 9

10 98. The half-life of Ra-224 is 4 days. How much of a 125g sample remains after 12 days? 99. How much of a 100g sample of 198 remains after 13.5 days? The half-life of Au-198 is 2.70 days What is the half-life of K-42 if 16.8 grams of a 268.8g sample remains after 49.6 hours? 101. List two effects of solar radiation How are the dark lines of the spectrum different than the colored lines? 103. What is the length and color of the shortest wavelength in the visible spectrum? Does this color contain more or less energy than yellow light (550nm)? 104. What is the first stage of the star cycle? 105. What is the last stage of the star cycle? 10

HEATING CURVE OF UNKNOWN SUBSTANCE

HEATING CURVE OF UNKNOWN SUBSTANCE TEMPERATURE ( C) SPRING 218 FINAL EXAM REVIEW STUDY GUIDE GENERAL CHEMISTRY 55 MULTIPLE CHOICE QUESTIONS STUDENTS CAN USE A CALCULATOR & TEACHER PROVIDED PERIODIC TABLE UNIT 3: THERMOCHEMISTRY VOCABULARY