Class C Drinking Water Practice Test 65 Questio aq aq aq aq aq aq aq
ns And multiple choice Answers
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Why does filtration typically follow PAC addition in a water treatment plant?
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A. Filters are necessary to provide the contact time for PAC to be effective.
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B. PAC creates turbidity which must be removed before distribution.
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C. Chlorine in the filters will deactivate the PAC.
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D. The PAC must be applied as "cap" on the filter media for it to be effective. -
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** C. Chlorine in the filters will deactivate the PAC.
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Aluminum, zinc, and magnesium are often used as anodes to prevent corrosion to other metals. Wher
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e does aluminum, zinc, and magnesium place in the galvanic series? -
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** as the most active metals
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In the corrosion Cell, the anode is the... -
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** positive pole
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metallic corrosion in potable water is always the result of -
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** an electrochemical reaction
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if the result of the Langelier index test on water in a distribution system is positive, then which of the f
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
ollowing statements is correct... aq aq aq
1. the water in the distribution system is corrosive
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2. the water in the distribution system is scale forming
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3. the source water entering the conventional filter plant is aggressive
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4. the well water will need ion exchange softening -
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** the water in the distribution system is scale forming
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special steel specimens called coupons are inserted into a water main. After several months, the speci
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mens are removed from the main. All coupons have lost weight over the period of time. What does thi
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
s indicate? -
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, ** the water is corrosive
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The location where metal is lost in a corrosion cell is called the
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A. anode
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B. cathode
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C. electrolyte
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D. dielectric -
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** A. anode
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The operator of the water system is experiencing an increased amount of water leaks in the system, a
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
nd lab results for lead and copper show an increase in both over time. The operator suspects corrosion
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
is taking place in the system. Which lab tests listed will help confirm that corrosion is taking place?
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A. Dissolved oxygen, TDS, temperature
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B. Temperature, pH, ammonia
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C. Dissolved oxygen, alkalinity, temperature
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D. Dissolved oxygen, pH, coupon analysis -
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** D. Dissolved oxygen, pH, coupon analysis
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The reaction of dissolved oxygen with ferrous ions is reduced during which condition?
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A. High pH values
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B. Low pH values
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C. Low flow velocity
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D. Low water temperatures -
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** B. Low pH values
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What is the term for an insulator used to prevent corrosion by separating two dissimilar metals?
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A. dielectric
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B. sacrificial cathode
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, C. sacrificial anode
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D. inhibitor -
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** A. dielectric
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Which chemical can be used to mask red water problems by bonding with iron, but could increase corr
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
osion by reducing calcium carbonate scale forming ability?
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A. Sodium hypochlorite
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B. Hydrofluosalicic acid
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C. Sodium hexametaphosphate
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D. Zinc orthophosphate -
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** C. Sodium hexametaphosphate
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Which of the elements or compounds listed below is considered to be the most corrosive component
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of water chemistry?
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A. Lead aq
B. Copper aq
C. Carbon Monoxide
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D. Dissolved Oxygen -
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** D. Dissolved Oxygen
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A dosage of three parts of chlorine to one part ammonia will form what compound?
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A. monochloramine
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B. dichloramine
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C. trichloramine
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D. nitrogen trichloride -
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** A. monochloramine
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ns And multiple choice Answers
aq aq aq aq
Why does filtration typically follow PAC addition in a water treatment plant?
aq aq aq aq aq aq aq aq aq aq aq
A. Filters are necessary to provide the contact time for PAC to be effective.
aq aq aq aq aq aq aq aq aq aq aq aq aq
B. PAC creates turbidity which must be removed before distribution.
aq aq aq aq aq aq aq aq aq
C. Chlorine in the filters will deactivate the PAC.
aq aq aq aq aq aq aq aq
D. The PAC must be applied as "cap" on the filter media for it to be effective. -
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
** C. Chlorine in the filters will deactivate the PAC.
aq aq aq aq aq aq aq aq aq aq
Aluminum, zinc, and magnesium are often used as anodes to prevent corrosion to other metals. Wher
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
e does aluminum, zinc, and magnesium place in the galvanic series? -
aq aq aq aq aq aq aq aq aq aq aq aq
** as the most active metals
aq aq aq aq aq aq
In the corrosion Cell, the anode is the... -
aq aq aq aq aq aq aq aq aq
** positive pole
aq aq aq
metallic corrosion in potable water is always the result of -
aq aq aq aq aq aq aq aq aq aq aq
** an electrochemical reaction
aq aq aq aq
if the result of the Langelier index test on water in a distribution system is positive, then which of the f
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
ollowing statements is correct... aq aq aq
1. the water in the distribution system is corrosive
aq aq aq aq aq aq aq aq aq
2. the water in the distribution system is scale forming
aq aq aq aq aq aq aq aq aq
3. the source water entering the conventional filter plant is aggressive
aq aq aq aq aq aq aq aq aq aq aq
4. the well water will need ion exchange softening -
aq aq aq aq aq aq aq aq aq aq
** the water in the distribution system is scale forming
aq aq aq aq aq aq aq aq aq aq
special steel specimens called coupons are inserted into a water main. After several months, the speci
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
mens are removed from the main. All coupons have lost weight over the period of time. What does thi
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
s indicate? -
aq aq aq
, ** the water is corrosive
aq aq aq aq aq
The location where metal is lost in a corrosion cell is called the
aq aq aq aq aq aq aq aq aq aq aq aq
A. anode
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B. cathode
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C. electrolyte
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D. dielectric -
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** A. anode
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The operator of the water system is experiencing an increased amount of water leaks in the system, a
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
nd lab results for lead and copper show an increase in both over time. The operator suspects corrosion
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
is taking place in the system. Which lab tests listed will help confirm that corrosion is taking place?
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
aq
A. Dissolved oxygen, TDS, temperature
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B. Temperature, pH, ammonia
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C. Dissolved oxygen, alkalinity, temperature
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D. Dissolved oxygen, pH, coupon analysis -
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** D. Dissolved oxygen, pH, coupon analysis
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The reaction of dissolved oxygen with ferrous ions is reduced during which condition?
aq aq aq aq aq aq aq aq aq aq aq aq
A. High pH values
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B. Low pH values
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C. Low flow velocity
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D. Low water temperatures -
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** B. Low pH values
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What is the term for an insulator used to prevent corrosion by separating two dissimilar metals?
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
A. dielectric
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B. sacrificial cathode
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, C. sacrificial anode
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D. inhibitor -
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** A. dielectric
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Which chemical can be used to mask red water problems by bonding with iron, but could increase corr
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
osion by reducing calcium carbonate scale forming ability?
aq aq aq aq aq aq aq
A. Sodium hypochlorite
aq aq
B. Hydrofluosalicic acid
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C. Sodium hexametaphosphate
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D. Zinc orthophosphate -
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** C. Sodium hexametaphosphate
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Which of the elements or compounds listed below is considered to be the most corrosive component
aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq aq
of water chemistry?
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A. Lead aq
B. Copper aq
C. Carbon Monoxide
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D. Dissolved Oxygen -
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** D. Dissolved Oxygen
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A dosage of three parts of chlorine to one part ammonia will form what compound?
aq aq aq aq aq aq aq aq aq aq aq aq aq aq
A. monochloramine
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B. dichloramine
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C. trichloramine
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D. nitrogen trichloride -
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** A. monochloramine
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