WASTEWATER LAB ANALYST CERTIFICATION EXAM
QUESTION BANK
2025 COMPLETE CWEA LAB ANALYST ACCURATE
REAL XAM QUESTIONS WITH DETAILED ANSWERS
| ALREADY GRADED A+ | GUARANTEED
EXCELLENCE PASS
Which test would assess toxic effects on different life stages and/or growth and
reproduction of an organism? - ✔✔✔ Correct Answer > Chronic test
When performing a conductivity measurement, you should determine the
temperature of the samples+/- 0.5 C. If the temperature of the sample is not 25 C
- ✔✔✔ Correct Answer > Proceed with the analysis and adjust results for the
temperature difference according to instructions in the method
The quantity of chlorine that is converted to inert or less active forms of chlorine
by substances in wastewater - ✔✔✔ Correct Answer > Total combined chlorine
Before you perform an amperometric titration for total residual chlornie, what
two solutions should be added to the sample? - ✔✔✔ Correct Answer > Kl and
acetate buffer
(Potassium iodide)
,Which toxicity test is most challenging for use on samples with high BOD and/or
COD or high bacterial populations? - ✔✔✔ Correct Answer > Static test
The toxicant concentration estimated to produce death in a specified portion of
test organisms is the - ✔✔✔ Correct Answer > LC lethal concentration
When performing an amperometric titration for chlorine, how many milliliters of
sample should be analyzed? - ✔✔✔ Correct Answer > 200 mL
When using a spectrophotometer to measure chlorine, what wave length of light
should be used? - ✔✔✔ Correct Answer > 515 nm
An effluent with a high level of ammonia nitrogen has chlorine residual that is
mostly - ✔✔✔ Correct Answer > Combined chlorine
The mercuric nitrate titration technique for measuring chloride is falling into
disuse in the laboratory because the: - ✔✔✔ Correct Answer > technique is
lengthy and requires highly skilled instrument technicians to accurately analyze
the samples.
Standard phenylarsine oxide solution (PAO): - ✔✔✔ Correct Answer > should be
handled with caution because it is a severe poison.
Sample Protocol for chloride includes - ✔✔✔ Correct Answer > glass or plastic
container with no preservative
,Flow proportional sample. If total sample volume is 1 liter - ✔✔✔ Correct Answer
> 100ml
The incubator for the BOD determination should be monitored and recorded
daily. The incubator temperature should be: - ✔✔✔ Correct Answer > 20 degrees
+/-1 degree C
Laboratory data mistakes may be corrected by: - ✔✔✔ Correct Answer > lining
out the mistake with pen and writing the correct answer to the side of the first
with analyst initials and date
The sample receiving log must record time and date sampled: - ✔✔✔ Correct
Answer > sample collector, nature of sample, analyses to be performed,
preservatives, condition of sample and sample recipient.
Hood flow should be monitored and documented at: - ✔✔✔ Correct Answer >
100 linear feet per minute
During an acid base titration, the titrant is added to the sample with a: - ✔✔✔
Correct Answer > Buret
Separatory funnels are designed to facilitate liquid-liquid extractions. Liquid-liquid
extraction can be used to separate - ✔✔✔ Correct Answer > organic analytes
from the water by partitioning them into an organic solvent
At a given temperature the intensity of the acidic or basic character of a solution
is indicated by - ✔✔✔ Correct Answer > pH or Hydrogen ion activity
, A solution with a pH of 5 has a concentration of hydrogen ions that is how many
times higher than a solution with a pH if 7? - ✔✔✔ Correct Answer > 100 times
higher
A pH measurement requires the following: - ✔✔✔ Correct Answer > a voltmeter,
glass pH electrode, reference electrode, and temperature compensating device
Conductance measurements are temperature compensated to: - ✔✔✔ Correct
Answer > 25.0 C
The conductivity meter is calibrated with: - ✔✔✔ Correct Answer > .0100 N
potassium chloride standard
Alkalinity is reported as: - ✔✔✔ Correct Answer > alkalinity, mg CaCO3/L
The hardness determination by EDTA titration measures: - ✔✔✔ Correct Answer
> Calcium and Magnesium
The indicator for the hardness determination is: - ✔✔✔ Correct Answer >
eriochrome Black T
EPA acceptable primary standards for the turbidity determination include: - ✔✔✔
Correct Answer > formazine only
COD - ✔✔✔ Correct Answer > ((Blank-Sample) x M x 8000))/ml Sample
QUESTION BANK
2025 COMPLETE CWEA LAB ANALYST ACCURATE
REAL XAM QUESTIONS WITH DETAILED ANSWERS
| ALREADY GRADED A+ | GUARANTEED
EXCELLENCE PASS
Which test would assess toxic effects on different life stages and/or growth and
reproduction of an organism? - ✔✔✔ Correct Answer > Chronic test
When performing a conductivity measurement, you should determine the
temperature of the samples+/- 0.5 C. If the temperature of the sample is not 25 C
- ✔✔✔ Correct Answer > Proceed with the analysis and adjust results for the
temperature difference according to instructions in the method
The quantity of chlorine that is converted to inert or less active forms of chlorine
by substances in wastewater - ✔✔✔ Correct Answer > Total combined chlorine
Before you perform an amperometric titration for total residual chlornie, what
two solutions should be added to the sample? - ✔✔✔ Correct Answer > Kl and
acetate buffer
(Potassium iodide)
,Which toxicity test is most challenging for use on samples with high BOD and/or
COD or high bacterial populations? - ✔✔✔ Correct Answer > Static test
The toxicant concentration estimated to produce death in a specified portion of
test organisms is the - ✔✔✔ Correct Answer > LC lethal concentration
When performing an amperometric titration for chlorine, how many milliliters of
sample should be analyzed? - ✔✔✔ Correct Answer > 200 mL
When using a spectrophotometer to measure chlorine, what wave length of light
should be used? - ✔✔✔ Correct Answer > 515 nm
An effluent with a high level of ammonia nitrogen has chlorine residual that is
mostly - ✔✔✔ Correct Answer > Combined chlorine
The mercuric nitrate titration technique for measuring chloride is falling into
disuse in the laboratory because the: - ✔✔✔ Correct Answer > technique is
lengthy and requires highly skilled instrument technicians to accurately analyze
the samples.
Standard phenylarsine oxide solution (PAO): - ✔✔✔ Correct Answer > should be
handled with caution because it is a severe poison.
Sample Protocol for chloride includes - ✔✔✔ Correct Answer > glass or plastic
container with no preservative
,Flow proportional sample. If total sample volume is 1 liter - ✔✔✔ Correct Answer
> 100ml
The incubator for the BOD determination should be monitored and recorded
daily. The incubator temperature should be: - ✔✔✔ Correct Answer > 20 degrees
+/-1 degree C
Laboratory data mistakes may be corrected by: - ✔✔✔ Correct Answer > lining
out the mistake with pen and writing the correct answer to the side of the first
with analyst initials and date
The sample receiving log must record time and date sampled: - ✔✔✔ Correct
Answer > sample collector, nature of sample, analyses to be performed,
preservatives, condition of sample and sample recipient.
Hood flow should be monitored and documented at: - ✔✔✔ Correct Answer >
100 linear feet per minute
During an acid base titration, the titrant is added to the sample with a: - ✔✔✔
Correct Answer > Buret
Separatory funnels are designed to facilitate liquid-liquid extractions. Liquid-liquid
extraction can be used to separate - ✔✔✔ Correct Answer > organic analytes
from the water by partitioning them into an organic solvent
At a given temperature the intensity of the acidic or basic character of a solution
is indicated by - ✔✔✔ Correct Answer > pH or Hydrogen ion activity
, A solution with a pH of 5 has a concentration of hydrogen ions that is how many
times higher than a solution with a pH if 7? - ✔✔✔ Correct Answer > 100 times
higher
A pH measurement requires the following: - ✔✔✔ Correct Answer > a voltmeter,
glass pH electrode, reference electrode, and temperature compensating device
Conductance measurements are temperature compensated to: - ✔✔✔ Correct
Answer > 25.0 C
The conductivity meter is calibrated with: - ✔✔✔ Correct Answer > .0100 N
potassium chloride standard
Alkalinity is reported as: - ✔✔✔ Correct Answer > alkalinity, mg CaCO3/L
The hardness determination by EDTA titration measures: - ✔✔✔ Correct Answer
> Calcium and Magnesium
The indicator for the hardness determination is: - ✔✔✔ Correct Answer >
eriochrome Black T
EPA acceptable primary standards for the turbidity determination include: - ✔✔✔
Correct Answer > formazine only
COD - ✔✔✔ Correct Answer > ((Blank-Sample) x M x 8000))/ml Sample
