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CWEA GRADE I LABORATORY ANALYST EXAM||
ACTUAL STUDY GUIDE ALL QUESTIONS AND
100% CORRECT ANSWERS ALREADY GRADED
A+|| LAT4EST AND COMPLETE UPDATE 2025
WITH EXPERT VERIFIED SOLUTIONS|| ASSURED
PASS!!!
Chloride - ANSWER: - Major anion found in many natural waters
- Can impart salty taste in H2O
What increases concentration of chloride in wastewater - ANSWER: Chloride in
human diet and softeners flushed into sanitary sewer system
2 most prevalent methods of measuring chloride - ANSWER: argentometric and
mercuric nitrate
Argentometric - ANSWER: Titration of sample with standard solution of silver
nitrate (AgNO3)
- Indicator: Chromate ions (CrO4)
- End point: reddish silver chromate
Mercuric Nitrate - ANSWER: 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 presence of mercury
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Interference of Mercuric Nitrate Method - ANSWER: Sulfide, bromide,
orthophosphate (over 30 ppm), and iodide
Why does color change in water - ANSWER: Presence of decaying vegetable
matter, metal ions (ie. iron) or industrial and domestic pollution
How is color measured - ANSWER: Measured using visual comparison method
Visual comparison method - ANSWER: Sample compared to standards using
matched nessler tubes
- Standards prepared with solution containing cholorplatinate and cobaltous
chloride
Standard units for color - ANSWER: One unit= color resulting from 1 mg of
platinum/L
2 color reporting - ANSWER: True and Apparent
True color - ANSWER: Color from dissolved substances, determine using sample
treated to remove turbidity
Apparent Color - ANSWER: Includes dissolved and suspended solids
Conductivity - ANSWER: H2Os capability to pass electrical flow
Conductivity of pure water - ANSWER: 0
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Units of conductivity - ANSWER: micromhos/cm
Temperature conductivity should be read at - ANSWER: 25 degrees Celcius
How is conductivity affected - ANSWER: Mobility of ions, conductivity is
dependent on viscosity
Viscosity - ANSWER: A liquids ability to resist flow, higher the viscosity the
lower the flow
Relationship of temperature and viscosity - ANSWER: Inverse
Acid - ANSWER: A compound which liberates hydrogen ions and has a pH below
7.
Alkalinity: - ANSWER: The measurement of a sample's capacity to neutralize
acid.
Alkalinity measures - ANSWER: The carbonate, bicarbonate, and hydroxide ion
concentration found in water
Primary reason for measuring alkalinity - ANSWER: Used in control of many
water and wastewater unit processes
How is alkalinity measured - ANSWER: Titration of a sample with a standard
solution of either sulfuric acid or hydrochloric acid to predetermined pH endpoint
CWEA GRADE I LABORATORY ANALYST EXAM||
ACTUAL STUDY GUIDE ALL QUESTIONS AND
100% CORRECT ANSWERS ALREADY GRADED
A+|| LAT4EST AND COMPLETE UPDATE 2025
WITH EXPERT VERIFIED SOLUTIONS|| ASSURED
PASS!!!
Chloride - ANSWER: - Major anion found in many natural waters
- Can impart salty taste in H2O
What increases concentration of chloride in wastewater - ANSWER: Chloride in
human diet and softeners flushed into sanitary sewer system
2 most prevalent methods of measuring chloride - ANSWER: argentometric and
mercuric nitrate
Argentometric - ANSWER: Titration of sample with standard solution of silver
nitrate (AgNO3)
- Indicator: Chromate ions (CrO4)
- End point: reddish silver chromate
Mercuric Nitrate - ANSWER: 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 presence of mercury
,2|Pag e
Interference of Mercuric Nitrate Method - ANSWER: Sulfide, bromide,
orthophosphate (over 30 ppm), and iodide
Why does color change in water - ANSWER: Presence of decaying vegetable
matter, metal ions (ie. iron) or industrial and domestic pollution
How is color measured - ANSWER: Measured using visual comparison method
Visual comparison method - ANSWER: Sample compared to standards using
matched nessler tubes
- Standards prepared with solution containing cholorplatinate and cobaltous
chloride
Standard units for color - ANSWER: One unit= color resulting from 1 mg of
platinum/L
2 color reporting - ANSWER: True and Apparent
True color - ANSWER: Color from dissolved substances, determine using sample
treated to remove turbidity
Apparent Color - ANSWER: Includes dissolved and suspended solids
Conductivity - ANSWER: H2Os capability to pass electrical flow
Conductivity of pure water - ANSWER: 0
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Units of conductivity - ANSWER: micromhos/cm
Temperature conductivity should be read at - ANSWER: 25 degrees Celcius
How is conductivity affected - ANSWER: Mobility of ions, conductivity is
dependent on viscosity
Viscosity - ANSWER: A liquids ability to resist flow, higher the viscosity the
lower the flow
Relationship of temperature and viscosity - ANSWER: Inverse
Acid - ANSWER: A compound which liberates hydrogen ions and has a pH below
7.
Alkalinity: - ANSWER: The measurement of a sample's capacity to neutralize
acid.
Alkalinity measures - ANSWER: The carbonate, bicarbonate, and hydroxide ion
concentration found in water
Primary reason for measuring alkalinity - ANSWER: Used in control of many
water and wastewater unit processes
How is alkalinity measured - ANSWER: Titration of a sample with a standard
solution of either sulfuric acid or hydrochloric acid to predetermined pH endpoint
