Chemistry The Central Science

Chemistry: The Central Science 1. What is a unifying principle that explains a body of experimental observations? A) law B) hypothesis C) theory D) phenomena E) prediction Ans:  C 2. What term is a tentative explanation for observations that are made that result in the formulation of this concept? A) law B) hypothesis C) theory D) phenomena E) prediction Ans:  B 3. What is the term used for findings that are summarized based on a pattern or trend? A) law B) hypothesis C) theory D) phenomena E) prediction Ans:  A 4. Which of the following activities is not a part of good science? A) proposing a theory D) designing experiments B) developing a hypothesis E) indulging in speculation C) making quantitative observations Ans:  E 5. Which one of the following is a "substance" in the sense of the word as used in your textbook? A) air B) tap water C) seawater D) water E) toothpaste Ans:  D 6. Which of the following cannot be separated into a simpler substance by chemical means? A) element D) homogeneous mixture B) emulsion E) heterogeneous mixture C) compound Ans:  A 7. If a liquid contains 60% sugar and 40% water throughout its composition then what is it called? A) solute D) heterogeneous mixture B) compound E) solvent C) homogeneous mixture Ans:  C 8. Which of the following does not have a uniform composition throughout? A) element D) heterogeneous mixture B) compound E) solvent C) homogeneous mixture Ans:  D 9. Which of the following is not an S.I. base unit? A) meter B) ampere C) second D) gram E) Kelvin Ans:  D 10. The S.I. base unit of mass is A) mg. B) g. C) kg. D) metric ton. E) lb. Ans:  C 11. The S.I. prefix mega– (M) means A) 10–6. B) 10–3. C) 103. D) 106. E) 109. Ans:  D 12. The S.I. prefixes milli– and mega– represent, respectively: A) 106 and 10–6. D) 10–3 and 109. B) 10–3 and 106. E) 10–6 and 10–3. C) 103 and 10–6. Ans:  B 13. How many micrograms are in 65.3 kg? A) 0.653 ?g D) 6.53 × 10–8 ?g B) 6.53 × 107 ?g E) 6.53 × 1010 ?g C) 6.53 × 104 ?g Ans:  E 14. A dose of medication was prescribed to be 35 microliters. Which of the following expresses that volume in centiliters? A) 3.5 × 105 cL D) 3.5 × 10–4 cL B) 3.5 × 104 cL E) 3.5 × 10–3 cL C) 3.5 cL Ans:  E 15. How many milliliters is 0.0055 L? A) 0.55 mL B) 5.5 mL C) 0.5 mL D) 0.0000055 mL E) 182 mL Ans:  B 16. How many hertz is 600.11 MHz? A) 6.0011 × 10–4 Hz D) 6.0011 × 10–2 Hz B) 60.011 Hz E) 6.0011 × 108 Hz C) 6.0011 × 106 Hz Ans:  E 17. The distance between carbon atoms in ethylene is 134 picometers. Which of the following expresses that distance in meters? A) 1.34 × 10–13 m D) 1.34 × 10–7 m B) 1.34 × 10–12 m E) 1.34 × 10–6 m C) 1.34 × 10–10 m Ans:  C 18. Which of these quantities represents the largest mass? A) 2.0 × 102 mg D) 2.0 × 102 cg B) 0.0010 kg E) 10.0 dg C) 1.0 × 105 ?g Ans:  D 19. The mass of a sample is 550 milligrams. Which of the following expresses that mass in kilograms? A) 5.5 × 108 kg D) 5.5 × 10–6 kg B) 5.5 × 105 kg E) 5.5 × 10–1 kg C) 5.5 × 10–4 kg Ans:  C 20. The diameter of Earth is 12.7 Mm. Express this diameter in centimeters. A) 1.27 × 105 cm D) 1.27 × 108 cm B) 1.27 × 106 cm E) 1.27 × 109 cm C) 1.27 × 107 cm Ans:  E 21. How many mm3 are in 16.7cm3? A) 1.67 × 10–5 mm3 D) 1.67 × 104 mm3 B) 1.67 × 10–8 mm3 E) 1.67 × 10–4 mm3 C) 1.67 × 107 mm3 Ans:  D 22. A patient in the hospital is running a temperature of 39.5°C, what is this in Fahrenheit? A) 99°F B) 101.3°F C) 102.4°F D) 103.1°F E) 104°F Ans:  D 23. If normal body temperature is 98.6 °F then what is this in Celsius? A) 34°C B) 35.5°C C) 36.4°C D) 37°C E) 38.7°C Ans:  D 24. Express 122°F in °C. A) 50.0°C B) 64.4°C C) 67.8°C D) 162.0°C E) 219.6°C Ans:  A 25. The boiling point for liquid helium is 4 K, what is the temperature in Fahrenheit? A) –452.5°F B) –498.9°F C) –237.2°F D) 131.8°F E) 530.9°F Ans:  A 26. If the temperature is 38°F then what is the temperature in Kelvin? A) 3.33 K B) 100.4 K C) 276.5 K D) 311.15 K E) 235.15 K Ans:  C 27. Dry ice (carbon dioxide) changes from a solid to a gas at –78.5°C. What is this temperature in °F? A) –173°F B) –12.6°F C) –109°F D) –75.6°F E) None of the above are within 2°F of the right answer. Ans:  C 28. The boiling point for liquid nitrogen is 77 K, what is the temperature in Fahrenheit? A) –126.8°F B) –288.8°F C) –3211°F D) 176.8°F E) 662.3°F Ans:  C 29. Acetone, which is used as a solvent and as a reactant in the manufacture of Plexiglas®, boils at 56.1°C. What is the boiling point in degrees Fahrenheit? A) 159°F B) 133°F C) 101°F D) 69.0°F E) 43.4°F Ans:  B 30. Isopropyl alcohol, commonly known as rubbing alcohol, boils at 82.4°C. What is the boiling point in Kelvin? A) 387.6 K B) 355.6 K C) 323.6 K D) 190.8 K E) –190.8 K Ans:  B 31. Acetic acid boils at 244.2°F. What is its boiling point in degrees Celsius? A) 382.0°C B) 167.7°C C) 153.4°C D) 117.9°C E) 103.7°C Ans:  D 32. What is the volume of a container that contains 14.3 g of a substance having a density of 0.988 g/cm3? A) 14.1 cm3 B) 0.0691 cm3 C) 14.5 cm3 D) 141 cm3 E) 691 cm3 Ans:  C 33. If you have a graduated cylinder containing 15.5 mL and this volume changes to 95.2 mL after a metal with a mass of 7.95 g is dropped into the cylinder, what is the density of this metal? A) 0.0835 g/mL D) 10.0 g/mL B) 0.513 g/mL E) 9.97 × 10–2 g/mL C) 0.0718 g/mL Ans:  E 34. Iron has a density of 7.87 g/cm3. What mass of iron would be required to cover a football playing surface of 120 yd × 60 yd to a depth of 1.0 mm? (1 in = 2.54 cm) A) 76 kg B) 47 Mg C) 7.6 × 105 g D) 4.7 × 108 g E) 1.9 × 107 g Ans:  B 35. An empty flask's mass is 17.4916 g and its mass is 43.9616 g when filled with water at 20.0°C (d = 0.9982 g/mL). The density of “heavy water” at 20.0°C is 1.1053 g/mL. What is the mass of the flask when filled with heavy water at 20.0°C? A) 29.2573 g B) 46.8016 g C) 46.7489 g D) 29.3100 g E) 43.9140 g Ans:  B 36. A flask has a mass of 78.23 g when empty and 593.63 g when filled with water. When the same flask is filled with concentrated sulfuric acid, H2SO4, its mass is 1026.57 g. What is the density of concentrated sulfuric acid? (Assume water has a density of 1.00 g/cm3 at the temperature of the measurement.) A) 1.992 g/cm3 D) 1.598 g/cm3 B) 1.840 g/cm3 E) 0.543 g/cm3 C) 1.729 g/cm3 Ans:  B 37. Talc is a mineral that has low conductivity for heat and electricity and is not attacked by acid. It is used as talcum powder and face powder. A sample of talc weighs 35.97 g in air and 13.65 g in mineral oil (d = 1.75 g/cm3). What is the density of talc? A) 4.61 g/cm3 B) 2.82 g/cm3 C) 2.63 g/cm3 D) 2.44 g/cm3 E) 1.61 g/cm3 Ans:  A 38. Which of the following is a chemical change? A) boiling water D) condensing water vapor into rainfall B) melting wax E) carving a piece of wood C) broiling a steak on a grill Ans:  C 39. Which of these is an example of a physical property? A) corrosiveness of sulfuric acid B) toxicity of cyanide C) flammability of gasoline D) neutralization of stomach acid with an antacid E) lead becomes a liquid when heated to 601°C Ans:  E 40. Which one of these represents a physical change? A) water, when heated, forms steam B) bleach turns hair yellow C) sugar, when heated, becomes brown D) milk turns sour E) apples, when exposed to air, turn brown Ans:  A 41. Which one of these represents a chemical change? A) boiling water to form steam B) turning hair yellow with bleach C) melting butter D) mixing powdered charcoal and oxygen at room temperature E) cutting a bar of sodium metal into pieces with a knife Ans:  B 42. Which of the following is an extensive property of oxygen? A) boiling point D) density B) temperature E) mass C) average kinetic energy of molecules Ans:  E 43. When the value of something does not depend on the amount of the matter then what is this called? A) empirical property D) extensive property B) intensive property E) exclusive property C) inclusive property Ans:  B 44. Which of the following is an extensive property? A) density B) temperature C) mass D) specific heat E) pressure Ans:  C 45. The number 1.050 × 109 has how many significant figures? A) 2 B) 3 C) 4 D) 9 E) 13 Ans:  C 46. How many significant figures are in 0.006570? A) 3 B) 4 C) 5 D) 6 E) 7 Ans:  B 47. After carrying out the operations below, how many significant figures are appropriate to show in the result? (13.7 + 0.027) ÷ 8.221 A) 1 B) 2 C) 3 D) 4 E) 5 Ans:  C 48. The result of (3.8621 × 1.5630) – 5.98 is properly written as A) 0.06 B) 0.056 C) 0.0565 D) 0.05646 E) 0.056462 Ans:  A 49. Select the answer with the correct number of decimal places for the following sum: 13.914 cm + 243.1 cm + 12.00460 cm = A) 269.01860 cm D) 269.02 cm B) 269.0186 cm E) 269.0 cm C) 269.019 cm Ans:  E 50. How many significant figures does the sum 8.5201 + 1.93 contain? A) 1 B) 2 C) 3 D) 4 E) 5 Ans:  D 51. Select the answer that expresses the result of this calculation with the correct number of significant figures. A) 13.3568 B) 13.357 C) 13.36 D) 13.4 E) 13 Ans:  E 52. The average distance between the Earth and the moon is 240,000 miles. Express this distance in kilometers. (1 mi = 1609 m) A) 6.1 × 105 km D) 1.5 × 105 km B) 5.3 × 105 km E) 9.4 × 104 km C) 3.9 × l05 km Ans:  C 53. How many inches are in 382.5 cm? (1 in = 2.54 cm) A) 150.6 in B) 6.641 × 10–3 in C) 151 in D) 971.6 in E) 972 in Ans:  A 54. How many cubic inches are in 1.00 liter? (1 in = 2.54 cm) A) 61.0 in3 B) 155 in3 C) 394 in3 D) 1.64 × 104 in3 E) none of the above Ans:  A 55. Convert 500 milliliters to quarts. (1 L = 1.06 qt) A) 1.88 qt B) 0.472 qt C) 0.528 qt D) 4.72 × 105 qt E) 5.28 × 105 qt Ans:  C 56. Given that 1 in = 2.54 cm, 1 cm3 is equal to A) 16.4 in3. B) 6.45 in3. C) 0.394 in3. D) 0.155 in3. E) 0.0610 in3. Ans:  E 57. A large pizza has a diameter of 15 inches. Express this diameter in centimeters. (1 in = 2.54 cm) A) 38 cm B) 24 cm C) 18 cm D) 9.3 cm E) 5.9 cm Ans:  A 58. What is the volume in milliliters of a 32.0 oz can of juice? (1 fl oz = 29.6 mL) A) 1.08 mL B) 947 mL C) 0.925 mL D) 0.95 mL E) 1.1 mL Ans:  B 59. The speed needed to escape the pull of Earth's gravity is 11.3 km/s. What is this speed in mi/h? (1 mi = 1609 m) A) 65,500 mi/h D) 1090 mi/h B) 25,300 mi/h E) 5.02 × 10–3 mi/h C) 18,200 mi/h Ans:  B 60. The density of mercury, the only metal to exist as a liquid at room temperature, is 13.6 g/cm3. What is that density in pounds per cubic inch? (1 in = 2.54 cm; 1 lb = 454 g) A) 849 lb/in3 D) 0.491 lb/in3 B) 491 lb/in3 E) 1.83 × 10–3 lb/in3 C) 376 lb/in3 Ans:  D 61. Some molecules move with speeds approaching the "escape velocity" from Earth, which is 7.0 miles per second. What is this speed in cm/h? (1 mi = 1609 m) A) 313 cm/h D) 1.1 × 106 cm/h B) 4.1 × 105 cm/h E) 1.6 × 109 cm/h C) 4.1 × 109 cm/h Ans:  C 62. The city of Los Angeles is now approximately 2400 miles south of Alaska. It is moving slowly northward as the San Andreas Fault continues to slide. If Los Angeles is to arrive near Anchorage, Alaska, in 76 million years, at what average rate will it have to move in mm per month? (1 mi = 1609 m) A) 2.0 × 10–10 mm/mo D) 9.5 mm/mo B) 6.6 × 10–6 mm/mo E) 51 mm/mo C) 4.2 mm/mo Ans:  C 63. Which of the following speeds is the greatest? (1 mi = 1609 m) A) 40 mi/h D) 0.74 km/min B) 2.0 × 105 mm/min E) 400 m/min C) 40 km/h Ans:  A 64. The speed needed to escape the pull of Earth's gravity is 11.3 km/s. What is this speed in mi/h? (1 mi = 1609 m) A) 65,500 mi/h D) 1090 mi/h B) 25,300 mi/h E) 5.02 × 10–3 mi/h C) 18,200 mi/h Ans:  B 65. You prepare 1000 mL of tea and transfer it to a 1.00 quart pitcher for storage. Which of the following statements is true? (1 L = 1.06 qt) A) The pitcher will be filled to 100% of its capacity with no tea spilled. B) The pitcher will be filled to about 95% of its capacity. C) The pitcher will be filled to about 50% of its capacity. D) The pitcher will be completely filled and a small amount of tea will overflow. E) The pitcher will be completely filled and most of the tea will overflow. Ans:  D 66. Radio waves travel at the speed of light which is 3.00 × 108 m/s. How many minutes does it take for a radio message to reach Earth from Saturn if Saturn is 7.9 × 108 km from Earth? A) 4.4 × 10–2 min D) 44 min B) 1.6 × 105 min E) 2.6 min C) 4.0 × 1015 min Ans:  D 67. Radio waves travel at the speed of light which is 3.00 × 108 m/s. How many kilometers will radio messages to outer space travel in exactly one year? A) 9.46 × 1015 km D) 9.46 × 1012 km B) 7.30 × 108 km E) 3.33 × 10–3 km C) 7.10 × 1010 km Ans:  D 68. True or False: Matter is anything that has mass and occupies space. Ans:  True 69. True or False: When applying the scientific method, it is important to avoid any form of hypothesis. Ans:  False 70. True or False: When applying the scientific method, a model or theory should be based on experimental data. Ans:  True 71. True or False: A dip of vanilla ice cream is a pure substance. Ans:  False 72. True or False: The juice from an orange is a mixture. Ans:  True 73. True or False: A particular temperature in degrees Celsius is larger than the temperature in Kelvin. Ans:  False 74. True or False: Zero Kelvin < 0° Fahrenheit < 0° Celsius. Ans:  True 75. True or False: 77 K is colder than 4 K. Ans:  False 76. True or False: Rusting of a piece of iron under environmental conditions is a physical change. Ans:  False 77. True or False: The ripening of fruit, once picked, is an example of physical change. Ans:  False 78. True or False: The density of a substance is an intensive property. Ans:  True 79. True or False: The volume of a substance is an intensive property. Ans:  False 80. True or False: Boiling point and melting point are extensive properties. Ans:  False 81. True or False: The number 6.0448, rounded to 3 decimal places, becomes 6.045. Ans:  True 82. What is something that has a definite composition? Ans: pure substance 83. What is a combination of two or more substances in which the substances retain their distinct identities? Ans: mixture 84. What is a substance that cannot be separated into simpler substances by chemical means? Ans: element 85. What is a substance composed of atoms of two or more elements chemically united in fixed proportions? Ans: compound 86. What is the equation for the conversion of Celsius to Kelvin? Ans: °C + 273.15 = Kelvin 87. What is the equation used to calculate the mass from the density? Ans: mass = density × volume or m = dv 88. Give examples of three physical properties. Ans: (Answers will vary.) melting point, boiling point, density, color 89. Identify this process as a physical or chemical change: bacteria converts milk to yogurt. Ans: chemical 90. Give an example of an extensive property. Ans: (Answers will vary.) mass, length, volume 91. Give an example of an intensive property. Ans: (Answers will vary.) temperature, density, melting point, boiling point 92. If two numbers are added together, and one has 2 digits after the decimal point and the other has 1 digit after the decimal point, explain how to round the answer. Ans: The answer will have 1 digit after the decimal point because the least number of digits after the decimal point in the two numbers used in the calculation was 1. Use the least number of digits after the decimal point. 93. If two numbers are multiplied together, and one has 3 significant figures and the other has 4 significant figures, explain how to round the answer. Ans: The answer will have 3 significant figures because the least number of significant figures in the two numbers used in the calculation was 3. 94. ____________ is a substance composed of atoms of two or more elements chemically united in fixed proportions. Ans: Compound 95. __________ is a substance that cannot be separated into simpler substances by chemical means. Ans: Element 96. __________ is a combination of two or more substances in which the substances retain their distinct identities. Ans: Mixture 97. __________ is something that has a definite composition. Ans: Pure substance 98. _________, _________, and ________ are the three states of matter. Ans: Liquid, solid, and gas 99. _______________ has a uniform composition throughout. Ans: Homogeneous mixture 100. _______________ does not have a uniform composition throughout. Ans: Heterogeneous mixture 101. Melting ice is a __________ change. Ans: physical 102. Burning wood in a fireplace is a __________ change. Ans: chemical 103. ___________ tells how closely multiple measurements of the same thing are to one another. Ans: Precision 104. ___________ is the term used to indicate a measurement is accurate. (Hint: Often used when measuring the volume of a liquid.) Ans: Graduated or Calibrated 105. ____________ tells how close a measurement is to the true value. Ans: Accuracy 106. Briefly explain the relationship between hypothesis and experiment in the scientific method. Ans: A hypothesis should be capable of leading to a prediction which is testable by experiment. If the experimental result differs from the prediction, the hypothesis should be modified. 107. Explain the difference between a hypothesis and a theory. Ans: A hypothesis is a tentative explanation for observations made and a theory is a unifying principle that explains a body of experimental observations and the laws that are based on them. 108. Explain the difference between quantitative measurements and qualitative measurements. Ans: A quantitative measurement is expressed with a number and a qualitative measurement does not require an explicit measurement. 109. Explain the difference between a heterogeneous mixture and a homogeneous mixture. Ans: A homogeneous mixture has a uniform composition throughout and a heterogeneous mixture does not have a uniform composition throughout. 110. Discuss the benefits of using the metric system for measurements. Ans: All measurements in the metric system are a multiple of 10 therefore is makes it easy to simply move the decimal point. 111. Discuss the difference between the Celsius and Fahrenheit scale for measuring temperatures. Ans: 0°C = 32°F and 100°C = 212°F. To convert from °F to °C use the equation °C = (°F – 32°F) × 5°C/9°F and to convert from °C to °F use the equation °F = [9°F/5°C]( °C) + 32°F 112. Explain the difference between a physical property and a chemical property. Ans: A physical property can be observed and measured without changing the identity of the substance and a chemical property requires a chemical change from one substance to another substance. 113. Explain the difference between an extensive property and an intensive property. Ans: An extensive property depends on the amount of matter and an intensive property does not depend on the amount of matter. 114. Explain the rule for significant figures for addition and subtraction. Ans: The answer cannot have more digits to the right of the decimal point than any of the original numbers used in the calculation. 115. Explain the rule for significant figures for multiplication and division. Ans: The number of significant figures in the final product or quotient is determined by the original number that has the smallest number of significant figures. 116. Explain the difference between accuracy and precision. Ans: Accuracy is how a measurement is to the true value and precision is how close multiple measurements of the same thing are to one another.