Chem 100 Exam 1 Study Guide w answers PDF

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Chem 100 Exam 1 Study Guide 1. Tin melts at 232.0 C. What is this temperature in kelvin? a. –41.2 K b. 232.0 K c. 449.6 K d. 505.2 K e. 530.2 K ANS: D 2. Which of the following is the smallest mass? a. 1.5  108 pg b. 1.5  106 ng c. 1.5  103 g d. 1.5  10–1 mg e. 1.5  10–5 g ANS: E 3. The radius of an potassium atom is 0.227 nm. What is the radius in millimeters? a. 2.27  10–9 mm b. 2.27  10–8 mm c. 2.27  10–7 mm d. 2.27  10–6 mm e. 2.27  10–4 mm ANS: C 4. Which of the following volumes are equivalent to 75 mL? 1. 0.75 cm3 2. 7.5  10–2 L 3. 0.0075 L a. b. c. d. e.

1 only 2 only 3 only 1 and 2 1, 2, and 3

ANS: B 5. Two students independently determine the volume of water delivered by a 10.00-mL pipet. Each student takes 8 measurements, then computes the average volume delivered and the standard deviation. The results are tabulated below.

Student A

Average 10.4 mL

St. Dev. 0.7 mL

Student B

10.00 mL

0.02 mL

Which statement best describes the results? a. A: good precision, good accuracy. B: good precision, good accuracy. b. A: good precision, poor accuracy. B: poor precision, good accuracy. c. A: poor precision, good accuracy. B: good precision, poor accuracy. d. A: poor precision, poor accuracy. B: good precision, good accuracy. e. A: poor precision, poor accuracy. B: poor precision, poor accuracy. ANS: D 6. Express 0.00720 in exponential notation. a. 7.20  103 b. 7.2  10–3 c. 7.20  10–3 d. 7.2  103 e. 7.2000  10–3 ANS: C 7. Express 2.030  101 in standard notation. a. 0.2030 b. 2.030 c. 2.03 d. 20.3 e. 20.30 ANS: E 8. The volume of space occupied by a beryllium atom is 6.0  10–30 m3. What is this volume in units of nm3? a. 6.0  10–57 nm b. 6.0  10–21 nm c. 6.0  10–12 nm d. 6.0  10–3 nm e. 6.0  106 nm ANS: D 9. Convert 8.900 10–8 meters to nanometers and express the answer in standard notation using the correct number of significant figures. a. 89 nm b. 89.0 nm c. 89.00 nm d. 8.90 nm e. 0.8900 ANS: C

10. Convert 0.490 ng to milligrams and express the answer in scientific notation using the correct number of significant figures. a. 4.90  10–5 mg b. 4.90  10–7 mg c. 4.9  10–7 mg d. 0.490  10–8 mg e. 0.490  10–7 mg ANS: B

11. Round 0.00680483 to 3 significant figures. a. 0.00 b. 0.007 c. 0.00680 d. 0.006804 e. 0.006805 ANS: C 12. What is the correct answer to the following expression: (205.18 – 197.3)  6.226? Carry out the subtraction operation first. a. 1 b. 1.3 c. 1.27 d. 1.266 e. 1.2657 ANS: B 13. What is the correct answer to the following expression? 7.4576  10–2 + 4.11  10–5 + 6  10–4 = a. 7.  10–2 b. 7.5  10–2 c. 7.52  10–2 d. 7.522  10–2 e. 7.5217  10–2 ANS: C

14. If 12 ounces of a liquid has a mass of 317 g, what is the density of the liquid in grams per cubic centimeter? (29.6 cm3 = 1.00 oz.) a. 0.0013 g/cm3 b. 0.89 g/cm3 c. 1.1 g/cm3 d. 0.0013 g/cm3

e. 130 g/cm3 ANS: B 15. The density of ice at 0 C is 0.917 g/mL. What is the volume of 125 g of ice? a. 0.00734 mL b. 115 mL c. 124 mL d. 126 mL e. 136 mL ANS: E

16. A hypothesis is a a. mathematical formula that models a pattern of behavior. b. concise statement of a behavior that is always the same under the same conditions. c. set of experiments designed to test a theory. d. well-tested, unifying principle that explains a body of facts. e. tentative explanation or prediction based upon experimental observations. ANS: E 17. A theory is a a. concise statement of a behavior that is always the same under the same conditions. b. tentative explanation or prediction based upon experimental observations. c. mathematical formula that models a pattern of behavior. d. well-tested, unifying principle that explains a body of facts. e. set of quantitative numerical data. ANS: D 18. Which one of the following is most likely to be a homogeneous mixture? a. blood b. soil c. gasoline d. plain yogurt e. mortar (a mixture of calcium carbonate and sand) ANS: C 19. Which one of the following is most likely to be a heterogeneous mixture? a. vinegar (a mixture of acetic acid and water) b. blood c. antifreeze (a mixture of water and ethylene glycol) d. sodium chloride (table salt) dissolved in water e. the air trapped inside a car tire ANS: B

20. A pure substance composed of two or more different elements is a(n) ________. a. ion b. heterogeneous mixture c. chemical compound d. solid e. solution ANS: C 21. A(n) ________ is a pure substance that is composed of only one type of atom. a. ion b. solution c. element d. molecule e. gas ANS: C 22. Which one of the following substances is classified as a chemical compound? a. He b. Nb c. Na d. NO e. Co ANS: D 23. Which one of the following statements is not a comparison of physical properties? a. Potassium reacts with water more quickly than calcium reacts with water. b. The electrical conductivity of aluminum is greater than copper. c. The density of copper is less than the density of lead. d. The solubility of NaCl in hot water is greater than the solubility in cold water. e. The boiling point of water is greater than the boiling point of ethanol. ANS: A 24. Which of the following statements is/are CORRECT? 1. The conduction of electricity through copper wire is a chemical change. 2. The rusting of iron is a chemical change. 3. The evaporation of ammonia at -33.3 C is a chemical change. a. b. c. d. e.

1 only 2 only 3 only 2 and 3 1, 2, and 3

ANS: B 25. An intensive property of a substance is

a. b. c. d. e.

independent of the amount present. dependent on its volume, but not its mass. not affected by its temperature. dependent only on its temperature. dependent only on its mass and volume.

ANS: A 26. Which of the following are extensive properties: mass, volume, and/or density? a. mass only b. volume only c. density only d. mass and volume e. volume and density ANS: D

27. All of the following are examples of chemical change EXCEPT a. the dissolving of sugar in water. b. the rusting of iron. c. the combustion of gasoline. d. the tarnishing of silver. e. the decomposition of cinnabar (HgS) to mercury metal upon heating. ANS: A...