CWEA LABORATORY ANALYST EXAM REVIEW
2026 REAL EXAM VERSIONS WITH VERIFIED
SOLUTIONS GRADED A+
◉ The pH measurement is temperature dependent. Which
temperature measurement should always be reported to the nearest
degree Celsius for each pH measurement?
A. Sample
B. Ambient
C. Buffer
D. Equipment. Answer: A. Sample
Sample temperature affects pH, equipment adjusts conditions based
on pH .
◉ Report pH measurements in standard units to the nearest
A. 0.001
B. 0.01
C. 0.1
D. 1.0. Answer: C. 0.1
One decimal units represents normal operating conditions.
,◉ Neutral pH at 25 degrees C is 7.0. Neutral pH of a sample at 0
degrees C
A. Increases
B. Decreases
C. Stays same
D. Fluctuates. Answer: A. Increases
Temperature increases the neutral pH decreases and as temperature
decreases the neutral pH increases.
◉ The acid or base condition of a sample is expressed by its
A. Alkalinity
B. pH
C. Acidity
D. Conductivity. Answer: B. pH
Alkalinity and Acidity are the acid and base neutralizing capabilities.
◉ What is the affect of anaerobic conditions on the pH of
wastewater?
A. Buffers the pH
B. Raises the pH
C. Lowers the pH
D. Has no effect. Answer: C Lowers the pH
,◉ The pH reading is considered stable and drift free when?
A. The pH reading begins to slowly rise and drop in the opposite
direction
B. The pH reading changes fewer than 0.5 pH units within 60
Seconds
C. The pH reading changes fewer than 0.1 pH units
D. There is no further change in the temperature reading. Answer: C.
The pH reading changes fewer than 0.1 pH units
◉ The most common pH electrode fouling is coating with?
A. Gritty Material
B. Volatile Solids
C. Oily material and precipitated solids
D. Dissolved solids. Answer: C. Oily material and precipitated solids
Any material that coats the pH electrode and clogs junction will
cause interferences.
◉ Fresh pH buffer solutions should be prepared?
A. Daily
B. Weekly
C. Monthly
D. Per manufacturers specifications. Answer: A. Daily
, Working solutions should be replaced daily.
◉ What should an analyst do with the fill hold on refillable non
sealed pH electrodes during pH measurements?
A. Leave it covered
B. Immerse it in buffer
C. Immerse it in sample
D. Leave it uncovered. Answer: D. Leave it uncovered
This allows free-flow of electrolyte across electrode junction which if
interrupted causes an increase in response time and drift in reading.
◉ The hold time for a pH sample is?
A. 12 hours
B. 24 hours
C. 48 hours
D. None, analyze immediately. Answer: D. None analyze immediately
pH is not stable and will change over time.
◉ To avoid the gain or loss of dissolved gasses contributing to
acidity or alkalinity of a sample:
A. Avoid vigorous shaking or mixing of sample
B. Bubble air through solution
2026 REAL EXAM VERSIONS WITH VERIFIED
SOLUTIONS GRADED A+
◉ The pH measurement is temperature dependent. Which
temperature measurement should always be reported to the nearest
degree Celsius for each pH measurement?
A. Sample
B. Ambient
C. Buffer
D. Equipment. Answer: A. Sample
Sample temperature affects pH, equipment adjusts conditions based
on pH .
◉ Report pH measurements in standard units to the nearest
A. 0.001
B. 0.01
C. 0.1
D. 1.0. Answer: C. 0.1
One decimal units represents normal operating conditions.
,◉ Neutral pH at 25 degrees C is 7.0. Neutral pH of a sample at 0
degrees C
A. Increases
B. Decreases
C. Stays same
D. Fluctuates. Answer: A. Increases
Temperature increases the neutral pH decreases and as temperature
decreases the neutral pH increases.
◉ The acid or base condition of a sample is expressed by its
A. Alkalinity
B. pH
C. Acidity
D. Conductivity. Answer: B. pH
Alkalinity and Acidity are the acid and base neutralizing capabilities.
◉ What is the affect of anaerobic conditions on the pH of
wastewater?
A. Buffers the pH
B. Raises the pH
C. Lowers the pH
D. Has no effect. Answer: C Lowers the pH
,◉ The pH reading is considered stable and drift free when?
A. The pH reading begins to slowly rise and drop in the opposite
direction
B. The pH reading changes fewer than 0.5 pH units within 60
Seconds
C. The pH reading changes fewer than 0.1 pH units
D. There is no further change in the temperature reading. Answer: C.
The pH reading changes fewer than 0.1 pH units
◉ The most common pH electrode fouling is coating with?
A. Gritty Material
B. Volatile Solids
C. Oily material and precipitated solids
D. Dissolved solids. Answer: C. Oily material and precipitated solids
Any material that coats the pH electrode and clogs junction will
cause interferences.
◉ Fresh pH buffer solutions should be prepared?
A. Daily
B. Weekly
C. Monthly
D. Per manufacturers specifications. Answer: A. Daily
, Working solutions should be replaced daily.
◉ What should an analyst do with the fill hold on refillable non
sealed pH electrodes during pH measurements?
A. Leave it covered
B. Immerse it in buffer
C. Immerse it in sample
D. Leave it uncovered. Answer: D. Leave it uncovered
This allows free-flow of electrolyte across electrode junction which if
interrupted causes an increase in response time and drift in reading.
◉ The hold time for a pH sample is?
A. 12 hours
B. 24 hours
C. 48 hours
D. None, analyze immediately. Answer: D. None analyze immediately
pH is not stable and will change over time.
◉ To avoid the gain or loss of dissolved gasses contributing to
acidity or alkalinity of a sample:
A. Avoid vigorous shaking or mixing of sample
B. Bubble air through solution
