CHEMISTRY EXAM REVIEW AND ANSWERS



1. Which is the correct measurement for location marked by the arrow?

[pic]

|a. |17.076 |c. |17.76 |

|b. |17.8 |d. |17.7 |

2. Which is the correct measurement for location marked by the arrow?

[pic]

|a. |30.5 |c. |30.45 |

|b. |34.5 |d. |30.046 |

3. The accepted value is 29.35. Which correctly describes this student’s experimental data?

|Trial |Measurement |

|1 |29.48 |

|2 |28.97 |

|3 |29.27 |

|a. |accurate but not precise |c. |both accurate and precise |

|b. |precise but not accurate |d. |neither accurate nor precise |

4. The accepted value is 1.43. Which correctly describes this student’s experimental data?

|Trial |Measurement |

|1 |1.29 |

|2 |1.93 |

|3 |0.88 |

|a. |accurate but not precise |c. |both accurate and precise |

|b. |precise but not accurate |d. |neither accurate nor precise |

5. The accepted value is 15.63. Which correctly describes this student’s experimental data?

|Trial |Measurement |

|1 |12.84 |

|2 |13.02 |

|3 |12.96 |

|a. |accurate but not precise |c. |both accurate and precise |

|b. |precise but not accurate |d. |neither accurate nor precise |

6. Three different people weigh a standard mass of 2.00 g on the same balance. Each person obtains a reading of 7.32 g for the mass of the standard. These results imply that the balance that was used is ____.

|a. |accurate |c. |accurate and precise |

|b. |precise |d. |neither accurate nor precise |

7. How do conceptual problems differ from numeric problems?

|a. |Solutions to conceptual problems involve analysis, while numeric solutions do not. |

|b. |Logic is not usually involved in solving numeric problems. |

|c. |A plan is necessary to solve numeric problems, but is not for conceptual problems. |

|d. |Solutions to conceptual problems normally do not involve calculations. |

8. Which term is described as the amount of matter in an object?

|a. |density |c. |mass |

|b. |volume |d. |length |

9. Which of the following measurements (of different masses) is the most accurate?

|a. |3.1000 g |c. |3.122 22 g |

|b. |3.100 00 g |d. |3.000 000 g |

10. Which group of measurements is the most precise? (Each group of measurements is for a different object.)

|a. |2 g, 3 g, 4 g |c. |2 g, 2.5 g, 3 g |

|b. |2.0 g, 3.0 g, 4.0 g |d. |1 g, 3 g, 5 g |

11. In the measurement 0.503 L, which digit is the estimated digit?

|a. |5 |

|b. |the 0 immediately to the left of the 3 |

|c. |3 |

|d. |the 0 to the left of the decimal point |

12. Which of the following mass units is the largest?

|a. |1 cg |c. |1 mg |

|b. |1 dg |d. |1 ng |

13. What is the quantity 0.0075 meters expressed in centimeters?

|a. |0.075 cm |c. |7.5 cm |

|b. |0.75 cm |d. |70.5 cm |

14. What is the quantity 7896 millimeters expressed in meters?

|a. |7.896 m |c. |789.6 m |

|b. |78.96 m |d. |789,600 m |

15. What is the quantity 987 milligrams expressed in grams?

|a. |0.000 987 g |c. |9.87 g |

|b. |0.987 g |d. |98,700 g |

16. Which of the following equalities is NOT correct?

|a. |100 cg = 1 g |c. |1 cm3 = 1 mL |

|b. |1000 mm = 1 m |d. |10 kg = 1 g |

17. A theory is a ____.

|a. |proposed explanation for an observation |

|b. |well-tested explanation for a broad set of observations |

|c. |summary of the results of many observations |

|d. |procedure used to test a proposed explanation |

18. When a test instrument is calibrated, does its accuracy, precision, or reliability improve?

|a. |precision |c. |reliability |

|b. |accuracy |d. |all of the above |

19. Which is the part of an experiment that serves as the point of comparison for the results?

|a. |hypothesis |c. |constant |

|b. |independent variable |d. |control |

20. One characteristic of a scientific theory is that ____.

|a. |it can never be proved |c. |it cannot be modified |

|b. |it can be proved |d. |it summarizes a set of observations |

21. Which step in the scientific method requires you to use your senses to obtain information?

|a. |revising a hypothesis |c. |making an observation |

|b. |designing an experiment |d. |stating a theory |

22. Collaboration and communication are important in science because ____.

|a. |most research problems are not very complex |

|b. |most scientists have the knowledge to solve any scientific problem |

|c. |they increase the likelihood of a successful outcome |

|d. |they keep scientists from having to repeat experiments |

23. Which kind of graph would be best to use with these data?

M&M’s™ in a bag

|Color |Orange |Brown |Yellow |Green |Blue |Red |

|Percent |20 |13 |14 |16 |24 |13 |

|a. |Line graph |c. |Bar graph |

|b. |Circle graph |d. |None of the above |

24. Which is the correct measurement for location marked by the arrow?

[pic]

|a. |50.2 |c. |52 |

|b. |51.8 |d. |51 |

25. The graph represents the sales data for a particular product. In which week were 8 units sold?

[pic]

|a. |3rd week |c. |6th week |

|b. |4th week |d. |9th week |

26. What is the SI unit of mass?

|a. |liter |c. |candela |

|b. |joule |d. |kilogram |

Significant Figures

27. Which is the sum of these values, to the appropriate number of significant digits?

17.358 + 3.502 + 20.14 =

|a. |41 |c. |41.000 |

|b. |41.00 |d. |41.0 |

28. Which is the product of these numbers, to the appropriate number of significant digits?

56.2 × 9.2057 =

|a. |517 |c. |517.36 |

|b. |517.4 |d. |517.00 |

29. Which of the following measurements contains two significant figures?

|a. |0.004 00 L |c. |0.000 44 L |

|b. |0.004 04 L |d. |0.004 40 L |

30. How many significant digits are in the value 530,405,000? 6

31. How many significant digits are in the value 0.0050340? 5

32. According to rounding rules for addition, the sum of 27.1, 34.538, and 37.68 is ____.

|a. |99.318 |c. |99.31 |

|b. |99.3 |d. |99 |

33. Which value has only 4 significant digits?

|a. |6.930 |c. |8450 |

|b. |0.0450 |d. |0.392 |

34. How many significant figures are in the measurement 0.003 4 kg?

|a. |two |c. |five |

|b. |four |d. |This cannot be determined. |

35. What is the measurement 111.009 mm rounded off to four significant digits? 111.0 mm

36. How many significant figures are in the measurement 40,500 mg? 3

37. How many significant figures are in the measurement 811.40 grams? 5

38. Express the sum of 1111 km and 222 km using the correct number of significant digits.

|a. |1300 km |c. |1333 km |

|b. |1330 km |d. |1333.0 km |

39. Express the sum of 7.68 m and 5.0 m using the correct number of significant digits.

|a. |12.68 m |c. |13 m |

|b. |12.7 m |d. |10 m |

40. Express the product of 2.2 mm and 5.00 mm using the correct number of significant digits.

|a. |10 mm2 |c. |11.0 mm2 |

|b. |11 mm2 |d. |11.00 mm2[pic] |

41. Which of the following measurements is expressed to three significant figures?

|a. |3 [pic] 101 |c. |3.2 [pic] 101 |

|b. |3.0 [pic] 101 |d. |3.24 [pic] 101 |

Scientific Notation

42. The product of 2 × 104 cm and 4 × 10–12 cm, expressed in scientific notation is ___

8 x 10-8 cm2

43. The diameter of a carbon atom is 0.000 000 000 154 m. What is this number expressed in scientific notation? 1.54 x 10-7 m

44. The expression of 5008 km in scientific notation is 5.008 x 103 km

45. What is the result of multiplying 2.5 [pic] 1010 by 3.5 [pic] 10-7? 8750 ( 8.8 x 103

46. What is the result of adding 2.5 [pic] 105 and 3.5 [pic] 102? 2.5 x 105

47. What is the measurement 1042 L rounded off to two significant digits? 1000 ( 1.0 x 103

48. Express the product of 4.0 [pic] 10-2 m and 8.1 [pic] 102 m using the correct number of significant digits. 3.24 x 101 m2

Short Answer

49. Which kind of graph would be best to use with these data? line graph

|Amount of Salt added |0 g |2 g |5 g |10 g |15 g |

|Boiling temperature, °C |99.7 |101.2 |102.4 |106.9 |108.3 |

50. What is the difference between a qualitative measurement and quantitative measurement?

qualitative ( observations; quantitative ( numbers/calculations

51. A student conducts an experiment to determine the effect of adding salt on the boiling temperature of water. The results are shown below. (Table 1)

|Sample |Amount of Salt |Boiling Temperature |

|Sample 1 |0 g |100.0° C |

|Sample 2 |2 g |102.3° C |

|Sample 3 |5 g |104.8° C |

|Sample 4 |10 g |107.5° C |

a) What is the independent variable in this experiment? amount of salt

b) What is the dependent variable in this experiment? temperature of water

c) What is a value that should remain constant for all samples in this experiment?

amount of water

d) What is the control? water with no added salt

e) What is a reasonable hypothesis for this experiment?

As the salt content increases, the boiling temperature of water will increases.

52. Explain how accuracy and precision differ. Accuracy measures the closeness of one value to the accepted value. Precision compares measurements of a set of data to each other.

53. The following length measurements were taken by students using several different measuring devices. Find the average of the measurements. Make sure that your answer has the correct number of significant figures.

10.05 cm, 10.1 cm, 9.741 cm, 10.6 cm, 10.5 cm average = 10.2 cm

54. The data for two different measurements are shown below. Which experiment was more accurate? Explain your answer.

|Sample |Measured value |Accepted value |

|Distance |54,700 m |57,900 m |

|Mass |61.3 g |65.7 g |

55. Convert 600 mg to grams. 0.600 g

56. Express 0.05 grams in kilograms, using the correct abbreviations. 0.000 05 kg

57. Round off the measurement 0.003 095 5 m to three significant figures. 0.00310 m

58. What is the sum of 6.210 L and 3 L expressed in the correct number of significant digits? 9 L

59. Perform the following operation: 3.43 cm [pic] 5.2 cm. Make sure that your answer has the correct number of significant figures. 19 cm2

60. A car covers a distance of 112.6 km in 1.8 h. Calculate its speed in meters per second. (1000 m = 1 km)

112.6 km 1000 m 1 h 1 min =17.38 m/s

1.8 h 1 km 60 min 60 s

61. A football field is 300 feet long. If a paperclip is is 3.2 cm long, how many paperclips would fit along the length of a football field? (1 inch = 2.54 cm)

300 ft 12 in 2.54 cm 1 paperclip = 2857.5 paperclips

1 ft. 1 in 3.2 cm

-----------------------

distance is 94.47% accurate

mass is 93.30% accurate

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download