CWEA Grade I Laboratory Analyst |2024 Save
UPDATE |REAL EXAM QUESTIONS AND
VERIFIED ANSWERS/ACCURATE
SOLUTIONS |GET IT 100% CORRECT!!
ALREADY GRADED A+
Practice questions for this set
Learn 1 /7 Study using Learn
Chromogenic substrate (ei. ortho-nitrophenyl B D galactopyranoside (ONPG) or
chlorophenol red B D galactopyranoside (CPRG) are used to detect enzyme BD
galactosidase, this enzyme hydolyzes substrate and produces color change. Color
change indicates positive test for total coliforms at 18 and 24 h (ONPG) or 24 h
(CPRG).
Give this one a go later!
, 1 Chloride 2 Apparent Color
Principle of total coliform bacteria for
4 Mercuric Nitrate
enzyme substrate test
Press any key to continue Don't know? Continue
Terms in this set (169)
Chloride - Major anion found in many natural waters
- Can impart salty taste in H2O
What increases concentration of chloride in Chloride in human diet and softeners flushed into sanitary
wastewater sewer system
2 most prevalent methods of measuring argentometric and mercuric nitrate
chloride
Argentometric Titration of sample with standard solution of silver nitrate
(AgNO3)
- Indicator: Chromate ions (CrO4)
- End point: reddish silver chromate
, Mercuric Nitrate 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
Interference of Mercuric Nitrate Method Sulfide, bromide, orthophosphate (over 30 ppm), and iodide
Why does color change in water Presence of decaying vegetable matter, metal ions (ie. iron)
or industrial and domestic pollution
How is color measured Measured using visual comparison method
Visual comparison method Sample compared to standards using matched nessler tubes
- Standards prepared with solution containing
cholorplatinate and cobaltous chloride
Standard units for color One unit= color resulting from 1 mg of platinum/L
2 color reporting True and Apparent
True color Color from dissolved substances, determine using sample
treated to remove turbidity
UPDATE |REAL EXAM QUESTIONS AND
VERIFIED ANSWERS/ACCURATE
SOLUTIONS |GET IT 100% CORRECT!!
ALREADY GRADED A+
Practice questions for this set
Learn 1 /7 Study using Learn
Chromogenic substrate (ei. ortho-nitrophenyl B D galactopyranoside (ONPG) or
chlorophenol red B D galactopyranoside (CPRG) are used to detect enzyme BD
galactosidase, this enzyme hydolyzes substrate and produces color change. Color
change indicates positive test for total coliforms at 18 and 24 h (ONPG) or 24 h
(CPRG).
Give this one a go later!
, 1 Chloride 2 Apparent Color
Principle of total coliform bacteria for
4 Mercuric Nitrate
enzyme substrate test
Press any key to continue Don't know? Continue
Terms in this set (169)
Chloride - Major anion found in many natural waters
- Can impart salty taste in H2O
What increases concentration of chloride in Chloride in human diet and softeners flushed into sanitary
wastewater sewer system
2 most prevalent methods of measuring argentometric and mercuric nitrate
chloride
Argentometric Titration of sample with standard solution of silver nitrate
(AgNO3)
- Indicator: Chromate ions (CrO4)
- End point: reddish silver chromate
, Mercuric Nitrate 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
Interference of Mercuric Nitrate Method Sulfide, bromide, orthophosphate (over 30 ppm), and iodide
Why does color change in water Presence of decaying vegetable matter, metal ions (ie. iron)
or industrial and domestic pollution
How is color measured Measured using visual comparison method
Visual comparison method Sample compared to standards using matched nessler tubes
- Standards prepared with solution containing
cholorplatinate and cobaltous chloride
Standard units for color One unit= color resulting from 1 mg of platinum/L
2 color reporting True and Apparent
True color Color from dissolved substances, determine using sample
treated to remove turbidity
