MR. SURRETTE VAN NUYS HIGH SCHOOL CHAPTER 2: MATTER AND ENERGY WORKSHEET SOLUTIONS 1. NaCl (s) 1A. Sodium chloride is a pure compound. 2. Sugar water (aq) 2A. Sugar water is homogeneous mixture. 3. Copper oxide (s) 3A. Copper oxide is a pure compound. 4. Copper wire (s) 4A. Copper wire is a pure element. 5. Dry ice at room temperature 5A. physical change 6 An iron nail rusts in the backyard 6A. chemical change 7. Copper becomes copper oxide 7A. chemical change 8. This state of matter has the least restricted motion. 8A. gas 9. This state of matter usually has the highest density. 9A. solid 10. Water found on earth’s surface at 280 K is in this state of matter. 10A. liquid 11. These solids have a definite geometric pattern with repeating units. 11A. crystalline 12. Anything that takes up space and has mass. 12A. matter 13. Temperature is a form of this type of energy. 13A. kinetic 14. The amount of energy required to raise the temperature of one gram of water one degree Celsius. 14A. calorie 1|Page CHEMISTRY MR. SURRETTE VAN NUYS HIGH SCHOOL 15. Convert 459 J into Calories. 15A. (1) 459 J x 1 c x 1C = 0.109703633 C -----------------4.184 J 1000 c -1 (2) 1.09703633 x 10 C (3) 1.10 x 10-1 C 16. Convert 217 Calories into kwh. 16A. (1) 217 C x 1000 c x 4.184 J x 1 kwh -----------------------------1C 1c 3.6 x 106 J (2) 2.519611111 x 10-1 (3) 2.52 x 10-1 kwh 17. Convert 4589 calories into kilojoules. 17A. (1) 4589 c x 4.184 J x 1 kJ = 19.200376 kJ ----------------1c 1000 J (2) 1.9200376 x 101 kJ (3) 1.920 x 101 kJ 18. Convert 92 kwh into Calories. 18A. (1) 92 kwh x 3.6 x 106 J x 1c x 1C ---------------------- --------1 kwh 4.184 J 1000 c 4 (2) 7.915869981 x 10 C (3) 7.9 x 104 C 19. Convert 100.3o F to Celsius 19A. (1) Tc = (5/9) (TF – 32) (2) Tc = (5/9) (100.3 – 32) (3) Tc = (5/9) (68.3) (4) Tc = 37.94444444 oC (5) Tc = 37.9 oC 2|Page CHEMISTRY MR. SURRETTE VAN NUYS HIGH SCHOOL 20. Convert – 60o C to Kelvin 20A. (1) Tc = T – 273 (2) T = Tc + 273 (3) T = (- 60o) + 273 (4) T = 213 K (5) T = 213 K 21. Convert 78o F to Kelvin 21A. (1) Tc = (5/9) (TF – 32) (2) Tc = (5/9) (78 – 32) (3) Tc = (5/9) (46) (4) Tc = 25.555555555556 oC (5) T = Tc + 273 (6) T = 25.555555555556 oC + 273 (7) T = 298.5555556 K (8) T = 299 K 22. A solid cube 3 cm on a side has a mass of 40 g. What is its density ? 22A. (1) Vcube = s3 (2) V = (3 cm)3 (3) V = 27 cm3 (4) = m / V (5) = 40 g / 27 cm3 (6) = 1.481481 g/cm3 (7) = 1.5 g/cm3 23. Calculate the calories required to heat 750 grams of lead from 15oC to 82oC. 23A. (1) From the Heat Capacities data table: Pb = 0.031 cal/deg/gm (2) 750 g Pb (0.031 cal/deg) ------------------ = 23.25 cal/deg 1g (3) 67oC (23.25 calories) ------------------- = 1558 calories 1oC 3|Page CHEMISTRY MR. SURRETTE VAN NUYS HIGH SCHOOL 24. Calculate the calories required to change 325 grams of ice at - 55oC to water at 70oC. 24A. Ice: - 55oC 0oC (1) From the Heat Capacities data table: H2O(solid) = 0.485 cal/deg/gm (2) 325 g Ice (0.485 cal/deg) ------------------ = 157.6 cal/deg 1g (3) 55oC (157.6 calories) ------------------ = 8668 calories 1oC Solid Liquid: (4) From the Heats of Transformation data table: H20 heat of fusion = 79.8 cal/gm (5) 325 g H2O (79.8 calories) ----------------- = 25,935 cal 1g Water: 0oC 70oC (6) From the Heat Capacities data table: H2O(liquid) = 1.000 cal/deg/gm (7) 325 g Water (1.000 cal/deg) ------------------1g = 325 cal/deg (8) 70oC (325 calories) ----------------- = 22,750 calories 1oC (9) Total calories: 8668 calories + 25,935 calories + 22,750 calories (10) Total calories = 57,353 calories 4|Page CHEMISTRY MR. SURRETTE VAN NUYS HIGH SCHOOL CHAPTER 2: MATTER AND ENERGY QUIZ SOLUTIONS Questions 1 - 3. Calculate the following and show your answer in scientific notation. 1. 1A. (1) (2) (3) (4) 2. 4.052 m + 3.8328 m ------------------------81.0 x 10-4 m (4.052 m + 3.8328 m) / 81.0 x 10-4 m (7.8848 m) / 81.0 x 10-4 m 973.34320988 9.73 x 102 (23.06 x 107 ft 2) (5.100 x 10-4 ft) -----------------------------------------4963 ft 2A. (1) (23.06 x 107 ft2)(5.100 x 10-4 ft) / 4963 ft (2) 23.6965545 ft2 (3) 2.370 x 101 ft2 3. A baking recipe calls for 2.5 quarts of milk. What is this in cm3? (1 L = 1.057 qt) 3A. (1) 2.5 qt x 1L x 1000 mL x 1 cm3 -------------------- --------1.057 qt 1L 1 mL 3 3 (2) 2.365184484 x 10 cm (3) 2.4 x 103 cm3 Questions 4 - 6. Indicate whether these statements describe a physical or a chemical property. 4. The boiling point of ethanol is 78o C. 4A. physical property 5. Sugar dissolves in tea when it is mixed. 5A. chemical property 6. Carbon monoxide, a poisonous gas, is formed when cars use gasoline. 6A. chemical property Questions 7 - 10. Indicate whether each of these is a physical or a chemical change. 7. Cutting a piece of metal. 7A. physical change 5|Page CHEMISTRY MR. SURRETTE VAN NUYS HIGH SCHOOL 8. The fogging of your car window on a rainy day. 8A. physical change 9. A dog farts. 9A. chemical change 10. Removing alcohol from beer. 10A. chemical change Questions 11 - 14. Determine if the following substances are: (a) pure or mixture (b) element, compound, homogeneous, or heterogeneous. 11. Baking soda (sodium bicarbonate) 11A. Baking soda is a pure compound. 12. Clear apple juice 12A. Clear apple juice is a homogeneous mixture. 13. Chocolate sundae 13A. A chocolate sundae is a heterogeneous mixture. 14. Aluminum foil 14A. Aluminum foil is a pure element. Questions 15 - 19. Solve the following problems. 15. Convert 20,125 calories into kilojoules. 15A. (1) 20,125 c x 4.184 J x 1 kJ = 84.203 kJ ----------------1c 1000 J (2) 8.4203 x 101 kJ 16. Convert 142 kwh into Calories. 16A. (1) 142 kwh x 3.6 x 106 J x 1 cal x 1C ----------------------------------1 kwh 4.184 J 1000 cal (2) 1.221797323 x 105 C (3) 1.22 x 105 C 6|Page CHEMISTRY MR. SURRETTE VAN NUYS HIGH SCHOOL 17. Convert – 80o C to Kelvin 17A. (1) TC = T – 273 (2) T = TC + 273 (3) T = (- 80o) + 273 (4) T = 193 K 18. A solid cube 4 cm on a side has a mass of 55 g. What is its density ? 18A. (1) Vcube = s3 (2) V = (4 cm)3 (3) V = 64 cm3 (4) = m / V (5) = 55 g / 64 cm3 (6) = 0.859375 g/cm3 (7) = 8.59375 x 10-1 g/cm3 (8) = 8.6 x 10-1 g/cm3 Questions 19 - 23. Answer the following questions. 19. This state of matter has the most restricted motion. 19A. solid 20. This state of matter usually has the lowest density. 20A. gas 21. Water found on the earth’s surface at 300 K is in this state of matter. 21A. liquid 22. Temperature is a form of this type of energy. 22A. kinetic 23. The amount of energy required to raise the temperature of one gram of water one degree Celsius. 23A. calorie 7|Page CHEMISTRY