CWEA grade 1 lab analyst practice test
part 2
What is chloride?
Major anion found in many natural waters - Can impart salty taste in H2O
1 multiple choice option
What increases the concentration of chloride in wastewater?
Chloride in human diet and softeners flushed into sanitary sewer system
2 multiple choice options
2 most prevalent methods of measuring chloride?
argentometric and mercuric nitrate
2 multiple choice options
What is the Argentometric method?
Titration of the sample with a standard solution of silver nitrate (AgNO3) - Indicator: Chromate
ions (CrO4) - End point: reddish silver chromate
3 multiple choice options
What is the Mercuric Nitrate method?
Titration with standard mercuric nitrate solution -pH must be adjusted between 2.3 and 2.8 -
Indicator: Diphenyl carbazone - End point: Change from blue to purple in the presence of
mercury
3 multiple choice options
Which of the following can be an Interference of the Mercuric Nitrate Method?
Sulfide, bromide, orthophosphate (over 30 ppm), and iodide
3 multiple choice options
Why does the color change in water?
a. Presence of decaying vegetable matter
b. metal ions (ie. iron)
c. industrial and domestic pollution
d. All of the above
, d
3 multiple choice options
How is color measured
Measured using visual comparison method
1 multiple choice option
What is the visual comparison method
Sample compared to standards using matching nessler tubes - Standards prepared with
solution containing chloroplatinate and cobaltous chlorid
2 multiple choice options
What is the standard unit for color?
One unit= color resulting from 1 mg of platinum/L
2 multiple choice options
What is 2-color reporting?
True and Apparent
1 multiple choice option
Define True color
Color from suspended solids, determine using sample treated to remove turbidity
3 multiple choice options
What is Apparent Color?
Color from both dissolved and suspended solids
3 multiple choice options
What is Conductivity?
H2O capability to pass electrical flow
2 multiple choice options
What is the conductivity of pure water?
0
3 multiple choice options
part 2
What is chloride?
Major anion found in many natural waters - Can impart salty taste in H2O
1 multiple choice option
What increases the concentration of chloride in wastewater?
Chloride in human diet and softeners flushed into sanitary sewer system
2 multiple choice options
2 most prevalent methods of measuring chloride?
argentometric and mercuric nitrate
2 multiple choice options
What is the Argentometric method?
Titration of the sample with a standard solution of silver nitrate (AgNO3) - Indicator: Chromate
ions (CrO4) - End point: reddish silver chromate
3 multiple choice options
What is the Mercuric Nitrate method?
Titration with standard mercuric nitrate solution -pH must be adjusted between 2.3 and 2.8 -
Indicator: Diphenyl carbazone - End point: Change from blue to purple in the presence of
mercury
3 multiple choice options
Which of the following can be an Interference of the Mercuric Nitrate Method?
Sulfide, bromide, orthophosphate (over 30 ppm), and iodide
3 multiple choice options
Why does the color change in water?
a. Presence of decaying vegetable matter
b. metal ions (ie. iron)
c. industrial and domestic pollution
d. All of the above
, d
3 multiple choice options
How is color measured
Measured using visual comparison method
1 multiple choice option
What is the visual comparison method
Sample compared to standards using matching nessler tubes - Standards prepared with
solution containing chloroplatinate and cobaltous chlorid
2 multiple choice options
What is the standard unit for color?
One unit= color resulting from 1 mg of platinum/L
2 multiple choice options
What is 2-color reporting?
True and Apparent
1 multiple choice option
Define True color
Color from suspended solids, determine using sample treated to remove turbidity
3 multiple choice options
What is Apparent Color?
Color from both dissolved and suspended solids
3 multiple choice options
What is Conductivity?
H2O capability to pass electrical flow
2 multiple choice options
What is the conductivity of pure water?
0
3 multiple choice options
