1. A chemical change always results characteristically in a change of 1) state; 2) form; 3) identity; 4) size; 5) shape. ANS: 3

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1 CHEMISTRY TEST NAME: INTRODUCTORY CHEMISTRY CONCEPTS DATE: Directions: For each of the following questions, choose the number that best answers the question and place it on your answer sheet. Directions: For each of the following questions, all major steps must be shown to receive full credit. Introductory Chemistry Concepts Level 1 Multiple Choice 1. A chemical change always results characteristically in a change of 1) state; 2) form; 3) identity; 4) size; 5) shape. 2. Which of the following is a chemical change? 1) evaporation of water 2) distillation of water 3) freezing of water 4) electrolysis of water 3. Chemical changes always involve 1) the absorption of energy; 2) the liberation of energy; 3) either the absorption or liberation of energy; 4) changes of state. 4. One physical property of sugar is its l) acidity; 2) reactivity; 3) flammability; 4) plasma qualities; 5) solubility. 5. The majority of chemical changes are 1) autothermic; 2) endothermic; 3) isothermic; 4) nonthermic; 5) exothermic. 6. The statement which describes a physical property of the element oxygen is 1) oxygen supports the burning of paper; 2) oxygen is needed for the rusting of iron; 3) oxygen must be present for food to decay; 4) oxygen has a density of 1.43 grams per liter; 5) oxygen is a component of water. 7. In any chemical reaction energy is 1) always absorbed; 2) always released; 3) released as heat; 4) usually not involved; 5) either absorbed or released. 8. Which of the following is not a chemical change? l) the dissolving of zinc by HCl 2) the exploding of gasoline 3) the corroding of a copper roof 4) the boiling of water 9. One chemical property of a substance is a description of its 1) odor; 2) density; 3) combustibility; 4) solubility; 5) none of these. 10. A new substance is formed as a result of a 1) physical change; 2) chemical

2 change; 3) physical property; 4) chemical property. 11. Chemical changes differ from physical changes because in chemical changes 1) new substances are formed. 3) a change in mass occurs. 2) properties change. 4) less energy change takes place. 12. When a substance changes and still retains its original properties, the change is called 1) chemical; 2) exothermic; 3) endothermic; 4) physical. 13. Energy is involved in both physical and chemical changes. The energy in chemical changes compared to physical changes is generally 1) greater; 2) the same; 3) no different; 4) greater in some but smaller in others. 14. Only a physical change takes place in l) producing water by burning hydrogen in air. 2) decomposing water into its elements by an electric current. 3) change water into ice by lowering its temperature. 4) changing water into hydrogen and oxygen by heating it to a very high temperature. 15. An example of a physical change produced by the addition of energy is 1) condensation of steam; 2) melting of ice; 3) burning of oil; 4) lighting of a match. 16. All of the following are chemical changes except the 1) souring of milk; 2) neutralization of an acid; 3) rusting of iron; 4) tarnishing of silver; 5) solution of sugar in water. 17. The properties of a substance that relate to its ability to form new substances are labeled 1) intensive; 2) extensive; 3) chemical; 4) physical. 18. Which statement describes a physical property of elemental oxygen? 1) Oxygen has a density of 1.43 g./l. 3) Oxygen is needed for human metabolism. 2) Oxygen supports the burning of paper. 4) Oxygen combines with iron to form rust. 19. The burning of hydrogen is a chemical change because 1) a gas changes to a liquid; 2) heat is produced; 3) a change in volume occurs; 4) a new substance with different properties forms. 20. An example of a chemical change is the l) condensation of steam; 2) corrosions of metals; 3) freezing of milk; 4) dissolving of sugar; 5) none of these.

3 21. An example of a physical change is 1) burning; 2) decaying; 3) melting; 4) rusting; 5) oxidation. 22. In a physical change of matter, 1) a chemical change takes place; 2) chemical properties change; 3) molecules break into atoms; 4) no new substances are formed; 5) heat is gained. 23.Which process is a chemical change? 1) the melting of ice 2) the burning of a candle 3) the magnetizing of steel 4) the liquefaction of oxygen 24. Which of the following is a chemical property of matter? 1) color 2) density 3) flammability 4) molecular mass 5) vapor pressure 25. An example of a chemical change is 1) burning magnesium; 2) boiling water; 3) tearing paper; 4) melting lead. 26. All of the following are physical properties of active metals except the ability to 1) conduct heat; 2) free hydrogen from water; 3) be hammered into sheets; 4) take high luster when polished. 27. An example of a physical change is the 1) color change of leaves in the autumn; 2) rust on a garden tool; 3) process called photosynthesis; 4) shredding a piece of paper. 28. An example of a chemical reaction is the 1) explosion of fireworks; 2) boiling of an egg; 3) freezing of ice; 4) drying of wet laundry. 29. According to makeup matter exists as 1) elements, solids, metals, liquids. 3) solids, liquids, gases, plasma. 2) elements, compounds, mixtures, solutions. 4) solids, compounds, mixtures, liquids. 30. The state of matter characterized by both a definite shape and a definite volume is a 1) fluid; 2) liquid; 3) solution; 4) gas; 5) none of these. 31. The state of matter which has no definite shape or volume is 1) gas; 2) liquid; 3) solid; 4) water. 32. Solids differ from liquids in that only samples of solids normally have definite

4 1) shapes; 2) volumes; 3) colors; 4) chemical compositions. 33. Matter that is characterized by neither a definite shape nor a definite volume is said to be 1) crystalline; 2) liquid; 3) solid; 4) fluid; 5) gaseous. 34. According to the Kinetic Theory, the physical state in which particles are forced to vibrate about fixed positions is 1) solid; 2) liquid; 3) gaseous; 4) fluid; 5) aqueous. 35. Which is characteristic of the gaseous phase? 1) Diffusion occurs slowly. 3) Particle arrangement in space is definite. 2) Compression is difficult. 4) Particles have minimum translational energy. 5) Complete occupation of containing vessel occurs. 36. The state of matter in which the molecules are practically independent of each other is 1) crystalline; 2) solid; 3) liquid; 4) gaseous. 37. Which property is characteristic of a liquid? 1) It has a constant volume. 4) Intermolecular forces are not very significant. 2) Intermolecular distances are large. 5) Expansion is appreciable as its temperature 3) Diffusion is faster than in a gas. changes. 38. Any sample of a compound 1) can consist of one element; 2) is homogeneous; 3) can have a varied chemical composition; 4) can be decomposed by physical change. 39. A material that is made up of more than one kind of atom 1) can not be a compound; 2) is an element; 3) may be a mixture; 4) must be a hydrate; 5) none of these. 40.Which is characteristic of a compound? 1) It can consist of a single element. 2) It is homogeneous. 3) Its chemical composition can be varied. 4) It can be decomposed by a physical change. 41.When a sample of a pure white substance is heated in a test tube, it gives off a reddishbrown colored gas and leaves a brown residue in the test tube. On the basis of this information it is most reasonable to conclude that the powder substance is 1) a compound; 2) an element; 3) either an element or a compound; 4) a solution. 42. The elements in a(n) are always in the same ratio. 1) compound 2) solution 3) alloy 4) mixture 5) none of these

5 43. Pure substances made of more than one element are call 1) compounds; 2) mixtures; 3) alloys; 4) solutions. 44. Two pure substances A and B react to form a new pure substance C. From this we may conclude that l) A and B are both elements; 2) C is a compound, A and B may or may not be elements; 3) C is an element, A and B are compounds; 4) A, B and C are all compounds. 45. An example of an element is 1) air; 2) milk; 3) mercury; 4) salt; 5) none of these. 46. When elements combine chemically, they always form 1) new elements; 2) atoms; 3) gases; 4) mixtures; 5) none of these. 47. Sugar is heated strongly in a test tube until it is completely changed into a charred black mass and drops of water. This experiment indicates that sugar is 1) an element; 2) a compound; 3) heterogeneous; 4) a solution; 5) a crystal. 48. A substance that can be broken up into simpler substances by ordinary chemical methods is l) an element; 2) a compound; 3) a mixture; 4) a salt. 49. A substance which cannot be further decomposed by ordinary chemical means is 1) water; 2) air; 3) sugar; 4) carbon; 5) steel. 50. A substance composed of two or more elements chemically united is called 1) a reactant; 2) a compound; 3) an isotope; 4) a mixture. 51. Compounds consist of two or more elements 1) combined in definite proportions by mass; 2) mixed together; 3) combined in varying proportions; 4) combined physically. 52. A prediction is a scientific hypothesis only if it 1) can be tested by some planned activity; 2) is based on experience; 3) will come true in the future; 4) states a generalization based on established fact. 53. Because scientists assume that there is a cause behind each occurrence, they are able to 1) make predictions about natural events; 2) control when most natural events will occur; 3) change most natural events; 4) make sure most natural events do not take place.

6 54. Three different observers measure the melting temperature of a substance and agree on the same value, but the value they obtain does not agree with the accepted value. Their measurements can be described as 1) both accurate and precise. 3) precise but not accurate. 2) neither accurate nor precise. 4) accurate but not precise. 55. Which of the following statements is not an observation? 1) The cat has soft fur. 2) The dog has sharp claws. 3) The duck s eyes are gray. 4) The tiger is more attractive than the alligator. 56. You see a friend s car in front of a restaurant. If you assume your friend is in the restaurant, you are making a(n) 1) decision; 2) theory; 3) inference; 4) law; 5) observation. 57.After his first attempt to solve a problem, a scientist usually 1) reports his conclusions to other scientists; 2) rechecks his work; 3) writes articles for scientific journals; 4) proceeds to find new and different problems. 58. In questioning a person s claims about a scientific matter, the most scientific attitude is to say 1) I don t believe. 2) Describe the evidence for your position. 3) What authority supports your position? 4) How do your results compare with those of other investigators? 59. The temporary answer that a scientist uses to guide an experiment is a 1) collection; 2) law; 3) record; 4) hypothesis; 5) all of these. 60. Scientists do not 1) search for evidence; 2) have a good imagination; 3) jump to conclusions; 4) test a hypothesis; 5) share information with other researchers. 61. Scientific theories l) always change; 2) never change; 3) change when new evidence is found; 4) always become laws; 5) none of these. 62. In drawing a scientific conclusion based on data collected by random sampling, scientists are aware that the conclusion 1) is tentative and may change as further data are obtained. 2) is true until proven incorrect. 3) should be withdrawn if others report contradictory results. 4) holds only for the sample which furnished the data. 63. Scientists communicate their findings to other scientists because 1) they are proud of their work; 2) they wish to gain fame; 3) other scientists may recheck their work; 4) an experiment is not finished until its results are announced.

7 64.A scientist s educated guess about a problem is usually called 1) a law; 2) a fact; 3) an opinion; 4) an hypothesis; 5) a principle. 65. Which of these examples best illustrate the if then reasoning of science? If the hypothesis is true, l) then society should take action; 2) this action should clear up the mystery; 3) the basic strategy will advance our argument; 4) this specific result or event will support it. 66. Which one of the following describes the process of science? 1) unorganized 2) ongoing 3) static 4) inconsistent 5) none of these 67. Which one of the following is characteristic of a scientific theory? 1) changeable 2) proven 3) permanent 4) untested 5) none of these 68. What can be gained in a systematic manner using scientific methods? 1) processes 2) information 3) models 4) controls 5) none of these 69. Which of the following is not an aspect of the scientific method? 1) making judgments based on experience or observation 2) maintaining a detached and impersonal approach 3) carrying out activities in an organized manner 4) establishing absolute truths 70. What is the major purpose of laboratory work in scientific research? 1) To verify previous work 2) To demonstrate known facts 3) To investigate questions 4) To reach final conclusions 71. Which one of the following is an observation rather than an interpretation? 1) The candle wax is changed to soot. 2) The top of the candle becomes wet with a colorless wax. 3) The candle burns to produce carbon dioxide and water. 4) The burning candle makes little or no sound. 5) The candle is made up of carbon and hydrogen. 72. Which of the following is an observation rather than an interpretation? 1) The candle wax is changed soot. 2) The candle burns to produce carbon dioxide and water. 3) The wick is made of three strands of string. 4) The candle is made of carbon and hydrogen. 5) The top of the candle becomes wet with a colorless wax.

8 73. Which of the following is an interpretation rather than an observation? 1) The candle wax is changed into soot. 2) The burning gives off no smell. 3) The wick is white were it emerges from the candle. 4) The candle is made of a white solid. 5) The candle is about 3/4 inch in diameter. 74. The Law of Definite Proportions applies to the definite composition by mass of 1) atoms; 2) elements; 3) compounds; 4) mixtures. 75. Two solid substances that have been stirred together but not chemically combined form a(n) 1) element; 2) compound; 3) mixture; 4) suspension; 5) solvent. ANS : All of the following are examples of extensive properties except 1) temperature; 2) volume; 3) weight; 4) mass. 77. Lead weighs grams per cubic centimeter. This statement represents lead s 1) shape; 2) mass; 3) hardness; 4) state; 5) density. 78.Which statement is correct for water? l) It is not an element because it can exist in three states. 2) It is a compound because all samples of water are alike. 3) It is not a compound because its properties are different from its elements properties. 4) It is not a mixture because it has a definite composition. 79. The smallest particle of an element which can enter into combination with other elements is l) an atom; 2) a molecule; 3) a crystal; 4) a macromolecule. 80. The atmosphere consists almost entirely of 1) hydrogen and oxygen; 2) carbon dioxide; 3) water and oxygen; 4) carbon dioxide and oxygen; 5) nitrogen and oxygen. 81. Which property would be most helpful in identifying a substance? 1) mass 2) state 3) volume 4) melting point 5) quantity 82. Measurements made during an experiment are what kind of observations? 1) qualitative 2) variable 3) quantitative 4) model 5) none of these

9 83. Heating a substance 1) never causes a chemical change; 2) may cause a chemical change; 3) always causes a chemical change; 4) has nothing to do with chemical changes. 84. Air is a mixture because it 1) is colorless; 2) is odorless; 3) does not have a uniform composition; 4) can be compressed. 85. Which is characteristic of mixtures? 1) Definite composition is present. 4) Components must be compounds. 2) Always have two phases present 5) Components can be separated by 3) Components must be elementary. physical means. 86. A reaction in which heat is given off is called: 1) exothermic; 2) endothermic; 3) fractional; 4) caloric. 87. A material that readily transmit heat and electricity is l) silicon; 2) copper; 3) plastic; 4) an insulator; 5) amorphous. 88. Which substance has a definite shape and a definite volume at STP? l) NaCl (aq) 2) Cl2(g) 3) CCl4(l) 4) AlCl3(s) 5) none of these 89. A mixture l) consists only of compounds; 2) consists only of elements; 3) may consist of elements and compounds; 4) never consists of both elements and compounds. 90. A substance that is made up of more than one kind of molecule is called a(n) l) element; 2) compound; 3) mixture; 4) atom. 91. A mixture consists of substances associated in l) definite proportions; 2) equal proportions; 3) any proportions; 4) chemical combinations. 92. Photosynthesis is an example of a chemical change brought about by 1) heat; 2) light; 3) solution in water; 4) electricity; 5) none of these. 93.Which of the following is a unit of area? 1) meter 2) cm 2 3) cm 3 4) liter 5) none of these

10 94. The SI unit for measuring pressure is the 1) pascal; 2) joule; 3) newton; 4) watt; 5) liter. 95. The SI unit for measuring force is the l) watt; 2) newton; 3) pascal; 4) joule; 5) none of these. 96. The SI unit for measuring energy is the 1) pascal; 2) newton; 3) joule; 4) watt; 5) gram. 97. Water in going through the three physical states would normally undergo 1) a change in mass. 3) a change in weight. 2) no energy changes. 4) a change in density. 5) a change in composition. 98. Factors that can change during an experiment are call 1) conclusions; 2) standards; 3) technology; 4) laws; 5) variables. 99. In addition to volume, which property of matter must be known to calculate mass? 1) index of refraction 3) specific heat 2) molecular weight 4) viscosity 5) density 100. A cube has a volume of 8.0 cm 3 and a mass of 21.6 grams. The density of the cube, in grams per cubic centimeter, is best expressed as 1) 2.7; 2) 2.15; 3) 0.37; 4) 0.73; 5) 0.98.