Test yourself with these sample questions

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You should AVERAGE answering each question in less than 100 seconds for this exam

Note: All of the following questions contain only one best answer. Circle the letter that best corresponds with the question.

TESTNote: All these statements are either True or False. Circle the one answer which best describes the truth of the statement.

1

Chlorine is toxic.

 

A.

 

True

 

B.

 

False

2

Chlorine is an irritant to breathing organs of the body.

 

A.

 

True

 

B.

 

False

3

Chlorine is only applied at the treatment plant influent (prechlorination) or at the effluent (postchlorination).

 

A.

 

True

 

B.

 

False

4

When chlorine combines with moisture, the resulting mixture is corrosive.

 

A.

 

True

 

B.

 

False

5

Leaking chlorine cylinders may be shipped if they are properly tagged.

 

A.

 

True

 

B.

 

False

6

To improve disinfection with chlorine, extending the contact time is generally more effective than increasing the chlorine dose.

 

A.

 

True

 

B.

 

False

7

Effluent from a wastewater treatment plant must be sterilized in order to protect the downstream users of the receiving waters.

 

A.

 

True

 

B.

 

False

8

When chlorine is applied directly into the chlorine contact basin, the continuous influent flow provides the needed mixing action.

 

A.

 

True

 

B.

 

False

9

Sulfur dioxide smells like chlorine.

 

A.

 

True

 

B.

 

False

10

You should never tamper with or apply heat to the fusible plug of a chlorine container.

 

A.

 

True

 

B.

 

False

11

Air padding is the practice of filling partially empty chlorine tank cars with air to prevent vaporization of the liquid chlorine.

 

A.

 

True

 

B.

 

False

12

Postchlorination is generally more effective in a well-clarified effluent than in a turbid one.

 

A.

 

True

 

B.

 

False

13

Hypochlorite compounds are available only in liquid form.

 

A.

 

True

 

B.

 

False

14

Hydrogen sulfide is found in most collection systems.

 

A.

 

True

 

B.

 

False

15

Postchlorination is used to disinfect the effluent from a wastewater treatment plant.

 

A.

 

True

 

B.

 

False

16

Knowledge of first aid is required of a competent treatment plant operator.

 

A.

 

True

 

B.

 

False

17

Never use soapy water to look for a sulfur dioxide leak.

 

A.

 

True

 

B.

 

False

18

Evaporators are used to remove moisture from the liquid chlorine delivery system

 

A.

 

True

 

B.

 

False

19

Ton chlorine tanks should be stored on the sides with their withdrawal valves positioned one above the other.

 

A.

 

True

 

B.

 

False

20

Emergency chlorine repair kits and approved respiratory protective devices should be stored inside the room where chlorine is used or stored.

 

A.

 

True

 

B.

 

False

21

The sulfur dioxide dechlorination reaction occurs in a relatively short time so no contact basin is needed.

 

A.

 

True

 

B.

 

False

22

A graduated cylinder measures liquid volumes more accurately than beakers but less accurately than burets.

 

A.

 

True

 

B.

 

False

23

A frosted band near the top of a pipet means the small amount of liquid remaining in the tip should be blown out and added to the receiving vessel.

 

A.

 

True

 

B.

 

False

24

If at all possible, samples for the BOD test should be collected after chlorination

 

A.

 

True

 

B.

 

False

25

A "blank" is used in lab tests for comparison purposes.

 

A.

 

True

 

B.

 

False

26

The time of day when a sample is collected will affect the sample's test results.

 

A.

 

True

 

B.

 

False

 27

 The end point of a titration is reached when there is a measurable change (often a color change) in the solution being tested

 

A.

 

True

 

B.

 

False

 

 

 

A.

 

True

 

B.

 

False

28. Acids and bases can safely be mixed together.

A. True

B. False

29. Both acids and bases can injure you.

A. True

B. False

30. A rubber bulb should usually be used to pipet samples except thick sludge samples, which it may be necessary to pipet by mouth.

A. True

B. False

31. When washing your hands after working with wastewater, the kind of soap is less important than the thorough use of soap.

A. True

B. False

32. Acid may be added to water, but not the reverse.

A. True

B. False

33. A wastewater with a pH of 8.3 is basic.

A. True

B. False

34. When preparing a composite sample, the individual samples must be vigorously mixed before the portion for the composite is withdrawn and then the entire composite sample should be vigorously mixed.

A. True

B. False

35. The concentration of hydrogen sulfide in wastewater flowing through a manhole is directly proportional to the concentration of H2S gas in the manhole atmosphere.

A. True

B. False

36. The saturation concentration of dissolved oxygen in water varies directly with temperature.

A. True

B. False

37. For practical purposes, one mg/L equals one part per million parts (ppm).

A. True

B. False

38. Effluent suspended solids samples may be collected any place in the effluent channel.

A. True

B. False

39. The BOD test is an indication of the organic content of wastewater.

A. True

B. False

40. A Class A-B-C fire extinguisher is usually the most suitable type for laboratory fire situations.

A. True

B. False

41. The suspended solids test should be tun on the same sample of mixed liquor that is used for the settleability test.

A. True

B. False

42. The range of values is determined by arranging the measurements in ascending or descending order.

A. True

B. False

43. The mean value and range of data describe the dispersion of data.

A. True

B. False

44. When a group of measurements includes one that is much larger than the others, the mean value will most nearly represent the average value.

A. True

B. False

45. The logarithm of a measurement is the sum of its characteristic and meniscus.

A. True

B. False

46. Moving averages are an effective way to detect trends because they smooth out fluctuations in the raw data.

A. True

B. False

47. A variance value is a trend value.

A. True

B. False

48. Presentation of data in tables, graphs, and charts makes it more accurate.

A. True

B. False

49. Instruments calibrated in the factory should be recalibrated after installation and use.

A. True

B. False

50. A "totalizer" is an averaging type of recorder.

A. True

B. False

51. Probability in percent is calculated the same way as the geometric mean.

A. True

B. False

52. Lab analyses of receiving water quality may be discarded once they have been reported to the appropriate regulatory agency.

A. True

B. False

53. Glassware or equipment may be held in your bare hands while heating in order to accurately control the rate of heating.

A. True

B. False

54. Test tubes are used for the settleable solids test.

A. True

B. False

55. The COD test is used to measure the strength of wastes that are too toxic for the BOD test.

A. True

B. False

56. Employers must provide employees with copies of material safety data sheets for any chemical substance the employee may come into contact with in the workplace.

A. True

B. False

57. Timed composite samples should be used to measure the temperature of the point source of interest.

A. True

B. False

58. The treatment plant superintendent is the only person responsible for laboratory safety.

A. True

B. False

59. Acids can injure you, but not bases.

A. True

B. False

60. Water may be added to acid, but not the reverse.

A. True

B. False

61. The pH scale ranges from 1 to 14.

A. True

B. False

62. The jar test is used to measure the conductivity of the water.

A. True

B. False

63. The Safe Drinking Water Act stipulates specific monitoring requirements for turbidity.

A. True

B. False

64. Dissolved oxygen improves the taste of water.

A. True

B. False

65. The reagent most frequently used in laboratory analyses is distilled water.

A. True

B. False

66. Measuring the intensity of the color enables the concentration of a substance in water to be measured.

A. True

B. False

67. A sample which has a high color intensity will have a low percent transmittance and a high absorbance value

A. True

B. False

68. In most natural waters, chloride is the principal cation.

A. True

B. False

69. The Modified Winkler procedure is used to measure dissolved mineral salts.

A. True

B. False

70. Temperature of the sample is a critical factor when conducting a Marble Test.

A. True

B. False

71. The formation of white floc during the DO test indicates that there is DO present in the sample.

A. True

B. False

72. As the temperature of water increases, the DO saturation value increases.

A. True

B. False

73. Nitrite represents the most completely oxidized form of nitrogen found in water.

A. True

B. False

74. A desiccator serves the same purpose as a muffle furnace.

A. True

B. False

75. Dry ice should be used to keep THM samples cool when shipping and storing.

A. True

B. False

76. If the manganese concentration in a sample cannot be determined immediately acidify the sample with acetic acid.

A. True

B. False

77. The MCL compliance for trihalomethanes is determined by the running average of four monthly averages.

A. True

B. False

78. In the laboratory, broken glass should be disposed of in wastebaskets.

A. True

B. False

79. Samples collected for monitoring of secondary contamination should be taken at a free-flowing outlet of water being delivered to the consumer.

A. True

B. False

80. The SDWA requires the same check sampling procedures whenever an MCL is exceeded for any contaminant.

A. True

B. False

81. Samples for turbidity must be taken at points where water enters the distribution system.

A. True

B. False

82. Laboratory analyses of water quality indicators are the only plant records that may not be discarded.

A. True

B. False

83. Frequent laboratory analysis of source water is a water agency's best protection against deliberate contamination.

A. True

B. False

84. The Total Coliform Test is a reliable indicator of potential presence of harmful organisms.

A. True

B. False

85. Field test kits can be relied on to prove the presence of a contaminant.

A. True

B. False

86. Methemoglobinemia is a disease caused by trihalomethanes.

A. True

B. False

87. To calculate the standard deviation, the geometric mean must first be calculated.

A. True

B. False

88. Farenheight, Centrigrade, Celcius and Kelvar are different scales used to measure temperature.

A. True

B. False

89. Always pour caustic into water, just like pouring acid into water.

A. True

B. False

90. If a strong alkaline solution floods the eyes, serious impairment of vision can be prevented if first aid is quickly applied.

A. True

B. False

91. Most preservation methods are only partially successful so all samples should be analyzed as soon as possible after they are collected.

A. True

B. False

92. The QA/QC procedures used in the field are the same as those used in the laboratory.

A. True

B. False

93. A D-type extinguisher should be available where burning metals might be encountered.

A. True

B. False

94. Caustic soda is a common name used for Sodium Hydroxide.

A. True

B. False

95. Specific conductivity is usually associated with a high TDS concentration.

A. True

B. False

96. Carbonate hardness is the only type of hardness encountered in water supplies

A. True

B. False

97

A confined space atmosphere may be hazardous if flammable gas or vapor levels exceed their flammable limits by more than 10 percent 

 

A.

 

True

 

B.

 

False

98

An ignition source like grinding or weldingcould cause a fire in a confined space

 

A.

 

True

 

B.

 

False

99

Entrapping design means a space that is very deep or dark

 

A.

 

True

 

B.

 

False

100

Heat stroke or heat-related exhaustion is hazardous because it limits your ability to get out of a confined space

 

A.

 

True

 

B.

 

False

101

Grounding connects electrical power to earth

 

A.

 

True

 

B.

 

False

102

Two-pronged plugs provide grounding

 

A.

 

True

 

B.

 

False

103

Electrical shock is unpleasant, but not dangerous

 

A.

 

True

 

B.

 

False

104

The longer your contact with electricity, the greater the shock

 

A.

 

True

 

B.

 

False

105

 Pipeting by mouth must never be permitted, unless a suction bulb is not available

 

A.

 

True

 

B.

 

False

106

 

 

A.

 

True

 

B.

 

False

Matching

For the next six questions: For each test or calculation listed in the left column, select the sample type from the right column that is most suitable for that test or calculation.

TEST

 

SAMPLE TYPE

1. Coliforms

 

a. Composite

2. Dissolved oxygen

 

b. Grab

3. pH

 

 

4. MCRT

 

 

5. Residual chlorine

 

 

6. Temperature

 

 



Possible definitions of the words listed below are given on the right. For each word listed on the left, try to find its definition on the right. Mark the number of the definition in the answer column for each word. For example, if the definition of a word is after the letter A, mark column A on your answer sheet after the word.

WORD

 

DEFINITION

1. Aliquot

 

a. Capacity to resist pH change

2. Ambient

 

b. Portion of a sample

3. Blank

 

c. Surrounding

4. Buffer

 

d. Test run without sample



Match the following names with the symbols:

Name

 

Chemical Symbol

1. Sulfuric acid

 

a. H2SO4

2. Calcium Carbonate

 

b. Al(SO4)3

3. Aluminum sulfate

 

c. NaCO3

4. Soda ash

 

d. CaCO3

Match the following elements with the symbols:

Name

 

Symbol

1. Carbon

 

a. H

2. Hydrogen

 

b. C

3. Oxygen

 

c. N

4. Nitrogen

 

d. O


Match the following names with the symbols:

Name

 

Symbol

1. Lye

 

a. ClO4¯

2. Perchlorate

 

b. CaO

3. Lime

 

c. CaCO3

4. Limestone

 

d. NaOH

Match the following names with the symbols:

Name

 

Symbol

1. Hydrogen sulfate

 

A. Na2SO4

2. Bisufate

 

B. HSO4¯

3. Ammonium sulfate

 

C. NH4S

4. Sodium Sulfate

 

D. (NH4)2SO4