EXAM QUESTIONS AND CORRECT ANSWERS
(VERIFIED ANSWERS) Q&A 2026-2027|INSTANT
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1. What is the primary purpose of chemical water analysis?
A. To change the color of water
B. To determine the physical and chemical characteristics of
water
C. To increase water temperature
D. To remove all microorganisms
Correct Answer: B
Rationale: Chemical water analysis evaluates water quality by
measuring parameters such as pH, alkalinity, hardness,
nutrients, and contaminants.
2. Which instrument is commonly used to measure pH in
water samples?
A. Turbidity meter
B. pH meter
C. Spectrophotometer
D. Conductivity probe
Correct Answer: B
,Rationale: A pH meter measures hydrogen ion activity and
determines whether water is acidic, neutral, or alkaline.
3. The pH scale measures:
A. Water temperature
B. Dissolved oxygen concentration
C. Acidity or alkalinity of water
D. Total dissolved solids only
Correct Answer: C
Rationale: pH indicates the concentration of hydrogen ions,
ranging from acidic (low pH) to alkaline (high pH).
4. A water sample with a pH of 7 is considered:
A. Strongly acidic
B. Neutral
C. Strongly alkaline
D. Contaminated
Correct Answer: B
Rationale: A pH of 7 represents neutral conditions where
hydrogen and hydroxide ions are balanced.
5. Which parameter measures the ability of water to resist
changes in pH?
,A. Hardness
B. Turbidity
C. Alkalinity
D. Conductivity
Correct Answer: C
Rationale: Alkalinity acts as a buffering capacity against sudden
pH changes.
6. Total hardness in water is mainly caused by:
A. Sodium and potassium
B. Calcium and magnesium
C. Chlorine and fluoride
D. Iron and manganese only
Correct Answer: B
Rationale: Calcium and magnesium ions are the primary
contributors to water hardness.
7. Which method is commonly used to determine water
hardness?
A. Titration
B. Filtration
C. Evaporation
D. Microscopy
, Correct Answer: A
Rationale: EDTA titration is commonly used to measure calcium
and magnesium hardness.
8. The unit commonly used for reporting water hardness is:
A. mg/L as CaCO₃
B. °C
C. ppm chlorine gas only
D. mL/min
Correct Answer: A
Rationale: Hardness is traditionally expressed as milligrams per
liter of calcium carbonate equivalent.
9. Turbidity in water is caused mainly by:
A. Dissolved gases
B. Suspended particles
C. Water temperature
D. pH changes only
Correct Answer: B
Rationale: Suspended solids such as clay, silt, and organic
matter reduce water clarity.
10. Which instrument measures turbidity?