Measurement and Sig Figs Review

Transcription

1 Name: Class: Date: Measurement and Sig Figs Review Matching Match each item with the correct statement below. a. absolute zero e. mass b. Kelvin temperature scale f. significant figure c. Celsius temperature scale g. precision d. weight h. accuracy 1. narrowness of range of measurements 2. kilogram is the SI base unit for this quantity 3. the force of gravity on an object 4. the non-si scale for temperature Multiple Choice Identify the choice that best completes the statement or answers the question. 5. The diameter of a carbon atom is m. What is this number expressed in scientific notation? a m b m c m d m 6. The expression of 5008 km in scientific notation is. a km b km c km d km 7. What is the result of adding and ? a b c d The closeness of a measurement to its true value is a measure of its. a. precision b. accuracy c. reproducibility d. usefulness 1

2 Name: 9. Which of the following measurements contains two significant figures? a L b L c L d L 10. Conversion factors are useful in solving problems in which a given measurement must be expressed in a. scientific notation. b. the correct number of significant digits. c. the correct precision. d. some other unit of measure. 11. Which group of measurements is the most precise? (Each group of measurements is for a different object.) a. 2 g, 3 g, 4 g b. 2.0 g, 3.0 g, 4.0 g c. 2 g, 2.5 g, 3 g d. 1 g, 3 g, 5 g 12. Which of the following measurements is expressed to three significant figures? a m b mg c km d mm 13. When a measurement is multiplied by a conversion factor, the numerical value a. and the actual size of the quantity measured are generally changed. b. is generally changed, but the actual size of the quantity measured remains the same. c. remains the same, but the actual size of the quantity measured is generally changed. d. and the actual size of the quantity measured remain the same. 14. Express the sum of 1111 km and 222 km using the correct number of significant digits. a km b km c km d km 15. A conversion factor that shows the relationship between grams and kilograms is a. b c d. 16. What is the volume of a salt crystal measuring m by m by m? a m 3 b m 3 c m 3 d m 3 2

3 Name: 17. What is the metric system prefix for the quantity ? a. centib. decic. kilod. micro- 18. Which of the following units is NOT an official SI unit? a. kilogram b. ampere c. mole d. liter 19. What is the SI unit of mass? a. liter b. joule c. candela d. kilogram 20. What is the temperature of absolute zero measured in C? a. 373 C b. 273 C c. 173 C d. 73 C 21. Which temperature scale has no negative temperatures? a. Celsius b. Fahrenheit c. Joule d. Kelvin 22. What is the boiling point of water in kelvins? a. 0 K b. 100 K c. 273 K d. 373 K 23. Which of the following mass units is the largest? a. 1 cg b. 1 dg c. 1 mg d. 1 ng 24. What is the temperature 34 C expressed in kelvins? a. 139 K b. 207 K c. 239 K d. 339 K 25. If the temperature changes by 100 K, by how much does it change in C? a. 0 C b. 37 C c. 100 C d. 273 C 3

4 Name: 26. Chlorine boils at 239 K. What is the boiling point of chlorine expressed in degrees Celsius? a. 93 C b. 34 C c. 61 C d. 34 C Use the table to help you answer the question(s). Commonly Used Metric Prefixes Prefix Meaning Factor mega (M) 1 million times larger than the unit it precedes 10 6 kilo (k) 1000 times larger than the unit it precedes 10 3 deci (d) 10 times smaller than the unit it precedes 10 1 centi (c) 100 times smaller than the unit it precedes 10 2 milli (m) 1000 times smaller than the unit it precedes 10 3 micro (µ) 1 million times smaller than the unit it precedes 10 6 nano (n) 1000 million times smaller than the unit it precedes 10 9 pico (p) 1 trillion times smaller than the unit it precedes What is the quantity meters expressed in centimeters? a cm b cm c. 7.5 cm d cm 28. Which of the following equalities is correct? a. 100 cg = 10 g b mm = 100 m c. 1 cm 3 = 1 ml d. 10 kg = 1 g 29. The quantity 44 liters expressed in cubic meters is. a m 3 b m 3 c m 3 d m Density is found by dividing. a. mass by volume b. volume by mass c. mass by area d. area by mass 4

5 Name: 31. What is the density of an object having a mass of 8.0 g and a volume of 25 cm 3? a g/cm 3 b. 2.0 g/cm 3 c. 3.1 g/cm 3 d. 200 g/cm As the density of a substance increases, the volume of a given mass of that substance. a. increases b. is not affected c. decreases d. fluctuates 33. The density of mercury is 5,427 kg/(m 3 ). If the density of water is 1.0 g/ml, will mercury float or sink in water? a. Mercury will float because the density of mercury is g/ml, which is less than the 1.0 g/ml density of water. b. Mercury will float because the density of mercury is g/ml, which is less than the 1.0 g/ml density of water. c. Mercury will sink because the density of mercury is g/ml, which is greater than the 1.0 g/ml density of water. d. Mercury will sink because the density of mercury is 5,427 g/ml, which is greater than the 1.0 g/ml density of water. 34. A train travels at a speed of 30 miles per hour. If 1 mile = 1.6 kilometers, how fast is the train traveling in kilometers per minute? a. 0.4 km/min b. 0.6 km/min c. 0.8 km/min d. 1.0 km/min Short Answer 35. What is the sum of 2.7 g and 2.47 g expressed in the correct number of significant digits? 36. What is the temperature 128 K expressed in degrees Celsius? 37. Express 0.05 grams in kilograms, using the correct abbreviations. 38. Express 0.06 liters in cubic meters, using the correct abbreviations. Essay 39. Explain the difference between precision and accuracy. Suppose you made three different mass measurements of a sugar sample you knew to have a mass of 1 g. How would you know whether or not the measurements were accurate? How would you know whether or not they were precise? Could the three measurements be precise, but not accurate? Explain. 40. Why is the metric system the preferred system of measurement for science? 41. Why is the density of a metal greater than the density of water? 5

6 Name: 42. Why do the densities of most substances decrease with temperature? 6

7 Measurement and Sig Figs Review Answer Section MATCHING 1. ANS: G 2. ANS: E 3. ANS: D 4. ANS: C MULTIPLE CHOICE 5. ANS: D 6. ANS: A 7. ANS: A 8. ANS: B 9. ANS: C 10. ANS: D 11. ANS: C 12. ANS: C 13. ANS: B 14. ANS: C 15. ANS: A 16. ANS: A 17. ANS: D 18. ANS: D 19. ANS: D 20. ANS: B 21. ANS: D 22. ANS: D 23. ANS: B 24. ANS: C 25. ANS: C 26. ANS: D 27. ANS: B 28. ANS: C 29. ANS: D 30. ANS: A 31. ANS: A 32. ANS: C 33. ANS: C 34. ANS: C 1

8 SHORT ANSWER 35. ANS: 5.2 g 36. ANS: C = K 273 = = 145 C 37. ANS: 0.05 g 1 kg/1000 g = kg 38. ANS: 0.06 L 1 m 3 /1000 L = m 3 ESSAY 39. ANS: Precision is the reproducibility of a measurement made under the same conditions; accuracy is the closeness of a measurement to the true value of the measurement. The three measurements would be precise if they were very close to each other in value; they would be accurate if they were close to the actual 1-g mass of the sample. If the measurements are very close to each other, they are precise, regardless of how close they are to the real value. Therefore, the measurements could be precise, but not accurate. 40. ANS: The metric system is important because of its simplicity and ease of use. The metric system is preferred for science because it is based on units that are multiples of ten, thus simplifying conversions between units. In addition, all necessary units can be derived from the seven basic units of the metric system. 41. ANS: Answers will vary. Students may offer one of the following, or both, explanations. Students may infer from the text that the metal s density is greater because the metal's atoms are heavier than the water molecules. Students may also infer that the metal s density is greater because the metal atoms are more closely packed than the water molecules. 42. ANS: The student should infer that this is because a substance's atoms or molecules tend to move farther apart with an increase in temperature. Consequently, the volume of the substance increases. There is no change in the mass of the substance, however, and therefore the density (mass/volume) decreases. 2