CWEA Lab Analyst Grade 1 EXAM
(COMPLETE ANSWERS elaborations)
answers 100% satisfaction guarantee
2026 UPDATE!!
What is chloride?
Major anion found in many natural waters - Can impart salty taste in H2O
What increases the concentration of chloride in wastewater?
Chloride in human diet and softeners flushed into sanitary sewer system
2 most prevalent methods of measuring chloride?
argentometric and mercuric nitrate
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
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
Which of the following can be an Interference of the Mercuric Nitrate Method?
Sulfide, bromide, orthophosphate (over 30 ppm), and iodide
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
How is color measured
Measured using visual comparison method
What is the visual comparison method
Sample compared to standards using matching nessler tubes - Standards prepared with
solution containing chloroplatinate and cobaltous chlorid
What is the standard unit for color?
One unit= color resulting from 1 mg of platinum/L
What is 2-color reporting?
True and Apparent
Define True color
Color from suspended solids, determine using sample treated to remove turbidity
What is Apparent Color?
Color from both dissolved and suspended solids
What is Conductivity?
H2O capability to pass electrical flow
What is the conductivity of pure water?
0
What are the Units of conductivity?
µS/cm (micromhos/cm)
What Temperature should conductivity be read at?
(COMPLETE ANSWERS elaborations)
answers 100% satisfaction guarantee
2026 UPDATE!!
What is chloride?
Major anion found in many natural waters - Can impart salty taste in H2O
What increases the concentration of chloride in wastewater?
Chloride in human diet and softeners flushed into sanitary sewer system
2 most prevalent methods of measuring chloride?
argentometric and mercuric nitrate
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
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
Which of the following can be an Interference of the Mercuric Nitrate Method?
Sulfide, bromide, orthophosphate (over 30 ppm), and iodide
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
How is color measured
Measured using visual comparison method
What is the visual comparison method
Sample compared to standards using matching nessler tubes - Standards prepared with
solution containing chloroplatinate and cobaltous chlorid
What is the standard unit for color?
One unit= color resulting from 1 mg of platinum/L
What is 2-color reporting?
True and Apparent
Define True color
Color from suspended solids, determine using sample treated to remove turbidity
What is Apparent Color?
Color from both dissolved and suspended solids
What is Conductivity?
H2O capability to pass electrical flow
What is the conductivity of pure water?
0
What are the Units of conductivity?
µS/cm (micromhos/cm)
What Temperature should conductivity be read at?
