CWEA GRADE 1 LAB ANALYST EXAM ACTUAL
EXAM 200 QUESTIONS AND CORRECT
DETAILED ANSWERS |A GRADE LATEST
UPDATE 2026
Agar medium is used for - CORRECT ANSWER ✔✔- Heterotrophic plate count
During acid base titration, titrant is added to the sample with - CORRECT ANSWER
✔✔- Buret
When preparing diluted calibration standards from a stock standard, use
combination of the following to get the most precise standard - CORRECT
ANSWER ✔✔- Class A volumetric flask and class A volumetric pipet
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
pH measurement requires the following - CORRECT ANSWER ✔✔- voltmeter, glass
pH electrode, reference electrode, and a temperature compensating device
Conductance measurements are temperature compensated to - CORRECT
ANSWER ✔✔- 25 degrees C
Conductivity meter is calibrated with - CORRECT ANSWER ✔✔- 0.0100 N
potassium chloride standard
1|Page
,Alkalinity is reported as - CORRECT ANSWER ✔✔- Alkalinity mg CaCO3/L
Chloride - CORRECT ANSWER ✔✔- - Major anion found in many natural waters
- Can impart salty taste in H2O
What increases concentration of chloride in wastewater - CORRECT ANSWER ✔✔-
Chloride in human diet and softeners flushed into sanitary sewer system
2 most prevalent methods of measuring chloride - CORRECT ANSWER ✔✔-
argentometric and mercuric nitrate
Precision is measured by - CORRECT ANSWER ✔✔- Analyzing replicate samples
Accuracy - CORRECT ANSWER ✔✔- The combination of bias and precision of an
analytical procedure, which reflects the closeness of a measured value to a true
value
Bias - CORRECT ANSWER ✔✔- Consistent deviation of measured values from the
true value, caused by systematic errors in a procedure
Precision - CORRECT ANSWER ✔✔- Measures the degree of agreement among
replicate analyses of a sample, usually expressed as the standard deviation
Random Error - CORRECT ANSWER ✔✔- Consistent deviation of measured values
from the true value, caused by systematic errors in a procedure
2|Page
, Total Solids - CORRECT ANSWER ✔✔- Well mixed sample is evaporated in a
weighed dish and dried to constant weight in an oven at 103-105 degrees C
Preparing Total solids evaporating dish - CORRECT ANSWER ✔✔- Ignite clean
evaporating dish at 550 furnace for 1 hour and store and cool in desicator
Analysis procedure of total solids - CORRECT ANSWER ✔✔- 1. Choose sample
volume that will yield residue between 2.5 and 200 mg
2. Dry evaporated sample for 1 hour in 103-105 degree C oven
3. Cool in desicator and weigh to constant weight
Constant weight for total solids - CORRECT ANSWER ✔✔- Weight change is less
than 4% of previous weight or 0.5 mg
Total Dissolved Solids - CORRECT ANSWER ✔✔- A well mixed sample is filtered
through standard glass fiber filter and filtrate is evaporated to dryness in weighed
dish and dried to constant weight at 180 degrees C
Preparing glass fiber filter disk - CORRECT ANSWER ✔✔- Apply vacuum and wash
disk with 3 successive 20 mL volumes of reagent grade water
Preparing evaporating dish for TDS - CORRECT ANSWER ✔✔- If volatile solids,
Ignite cleaned evaporating dish at 550 for 1 hour in furnace
If only TDS, heat cleaned dish to 180 for 1 hour
3|Page
EXAM 200 QUESTIONS AND CORRECT
DETAILED ANSWERS |A GRADE LATEST
UPDATE 2026
Agar medium is used for - CORRECT ANSWER ✔✔- Heterotrophic plate count
During acid base titration, titrant is added to the sample with - CORRECT ANSWER
✔✔- Buret
When preparing diluted calibration standards from a stock standard, use
combination of the following to get the most precise standard - CORRECT
ANSWER ✔✔- Class A volumetric flask and class A volumetric pipet
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
pH measurement requires the following - CORRECT ANSWER ✔✔- voltmeter, glass
pH electrode, reference electrode, and a temperature compensating device
Conductance measurements are temperature compensated to - CORRECT
ANSWER ✔✔- 25 degrees C
Conductivity meter is calibrated with - CORRECT ANSWER ✔✔- 0.0100 N
potassium chloride standard
1|Page
,Alkalinity is reported as - CORRECT ANSWER ✔✔- Alkalinity mg CaCO3/L
Chloride - CORRECT ANSWER ✔✔- - Major anion found in many natural waters
- Can impart salty taste in H2O
What increases concentration of chloride in wastewater - CORRECT ANSWER ✔✔-
Chloride in human diet and softeners flushed into sanitary sewer system
2 most prevalent methods of measuring chloride - CORRECT ANSWER ✔✔-
argentometric and mercuric nitrate
Precision is measured by - CORRECT ANSWER ✔✔- Analyzing replicate samples
Accuracy - CORRECT ANSWER ✔✔- The combination of bias and precision of an
analytical procedure, which reflects the closeness of a measured value to a true
value
Bias - CORRECT ANSWER ✔✔- Consistent deviation of measured values from the
true value, caused by systematic errors in a procedure
Precision - CORRECT ANSWER ✔✔- Measures the degree of agreement among
replicate analyses of a sample, usually expressed as the standard deviation
Random Error - CORRECT ANSWER ✔✔- Consistent deviation of measured values
from the true value, caused by systematic errors in a procedure
2|Page
, Total Solids - CORRECT ANSWER ✔✔- Well mixed sample is evaporated in a
weighed dish and dried to constant weight in an oven at 103-105 degrees C
Preparing Total solids evaporating dish - CORRECT ANSWER ✔✔- Ignite clean
evaporating dish at 550 furnace for 1 hour and store and cool in desicator
Analysis procedure of total solids - CORRECT ANSWER ✔✔- 1. Choose sample
volume that will yield residue between 2.5 and 200 mg
2. Dry evaporated sample for 1 hour in 103-105 degree C oven
3. Cool in desicator and weigh to constant weight
Constant weight for total solids - CORRECT ANSWER ✔✔- Weight change is less
than 4% of previous weight or 0.5 mg
Total Dissolved Solids - CORRECT ANSWER ✔✔- A well mixed sample is filtered
through standard glass fiber filter and filtrate is evaporated to dryness in weighed
dish and dried to constant weight at 180 degrees C
Preparing glass fiber filter disk - CORRECT ANSWER ✔✔- Apply vacuum and wash
disk with 3 successive 20 mL volumes of reagent grade water
Preparing evaporating dish for TDS - CORRECT ANSWER ✔✔- If volatile solids,
Ignite cleaned evaporating dish at 550 for 1 hour in furnace
If only TDS, heat cleaned dish to 180 for 1 hour
3|Page
