Water Treatment MCQ

Water Treatment MCQ

Water Treatment MCQ, MCQ on water treatment with answers, multiple-choice questions on water treatment engineering, MCQ on water treatment engineering chemistry, water MCQs with answers, water treatment questions and answers, water technology questions and answers, water purification questions and answers, Water Treatment MCQ, Engineering MCQ, engineering chemistry MCQ

Multiple Choice Questions (MCQ) on Fuels

Electrochemistry MCQ

multiple-choice Questions

Q.1. The purest form of natural water is

  • River water
  • Sea water
  • Underground water
  • Rain water

Answer: Rain water

Q.2. The alkaline hardness of water is due to the presence of the following salts of calcium and magnesium in water.

  • HCO3 only
  • HCO3 and CO32− only
  • SO42− only
  • HCO3 , CO32− , and OH only

Answer: HCO3 , CO32− , and OH only

Q.3. A sample of water contains 120 mg of Mg2+ per liter. The hardness of the sample of water in terms of CaCO3 equivalent is

  • 120 mg/L
  • 500 mg/L
  • 250 mg/L
  • 1000 mg/L

Answer: 500 mg/L

Q.4. The total hardness of a sample of water is 1.88°Cl eq. CaCO3 . Its hardness in ppm would be

  • 26.88
  • 18.8
  • 0.188
  • 34.65

Answer: 26.88

Q.5. The color obtained by adding EBT indicator to a sample of water containing Ca2+ and Mg2+ at pH = 9–10 is

  • Blue
  • Wine red
  • Pink
  • No colour

Answer: Wine red

Q.6. On boiling and filtering hard water, water sample contains

  • Temporary hardness
  • Permanent hardness
  • Both
  • None of the above

Answer: Permanent hardness

Q.7. The blow-down operation causes the removal of

  • Scales
  • Sludges
  • Acidity
  • Basicity

Answer: Sludges

Q.8. Scale formation in boiler-feed water is due to

  • Metallic deposition
  • Corrosion in boilers
  • Deposition of hard water
  • All the above

Answer: Deposition of hard water

Q.9. Scale formation is mainly due to which of the following salt present in boiler-feed water?

  • CaSO4
  • MgCO3
  • Na2 SO4
  • KCl

Answer: CaSO4

Q.10. Solubility of CaSO4 salt present in water

  • Increases with increase in temperature
  • Decreases with increase in temperature
  • Remain unchanged with increase in temperature
  • Not having any defi nite change with increase in temperature.

Answer: Decreases with increase in temperature

Q.11. EDTA method is used for determining

  • Temporary hardness
  • Permanent hardness
  • Temporary and permanent hardness
  • Alkalinity

Answer: Temporary and permanent hardness

Q.12. When phenolphthalein alkalinity, P = M then alkalinity is due to

  • OH
  • CO32−
  • HCO3
  • CO32− and HCO3

Answer: CO32−

Q.13. The permanent hardness of water cannot be removed by

  • Lime soda process
  • Permutit process
  • Boiling
  • Demineralization process

Answer: Boiling

Q.14. Permutit is chemically

  • Sodium silicate
  • Hydrated sodium alumino silicate
  • Aluminium silicate
  • All the above

Answer: Hydrated sodium aluminosilicate

Q.15. Hard water is not suitable for use in boilers because

  • It has a higher boiling point
  • It leads to scale formation in the boiler
  • It consumes more fuel in steam generation
  • The quality of steam generated is not good

Answer: It leads to scale formation in the boiler

Q.16. Which of the following substances is capable of removing dissolved oxygen from water?

  • Cl2
  • N2 H4
  • Na2 SO4
  • CaOCl2

Answer: N2 H4

Q.17. Sterilization of water can be done by using

  • H2 O2
  • O2
  • Cl2
  • NaOH

Answer: Cl2

Q.18. Coagulants help in settling of

  • Suspended impurities only
  • Finely suspended impurities only
  • Colloidal particles only
  • Both the suspended and colloidal particles

Answer: Both the suspended and colloidal particles

Q.19. 1 ppm of K+ present in a sample of demineralized water is equal to

  • 4.3478 × 10– 8 mol L–1
  • 2.564 × 10– 10 mol L–1
  • 2.564 × 10– 5 mol L–1
  • None of the above

Answer: 2.564 × 10– 5 mol L–1

Q.20. Calgon is a name given to

  • Sodium silicate
  • Sodium hexameta phosphate
  • Sodium meta phosphate
  • Calcium phosphate

Answer: Sodium hexameta phosphate

Q.21. Permutit exchanges Ca2+ and Mg2+ ions present in hard water with

  • Zeolite ions
  • H + ions
  • Na + ions
  • None of these

Answer: Na + ions

Q.22. The exhausted zeolite can be regenerated by treating it with

  • 10% NaCl solution
  • 50% NaCl solution
  • 10% HCl solution
  • 50% HCl solution

Answer: 10% NaCl solution

Q.23. Brackish water contains dissolved

  • CaSO4
  • MgCl2
  • NaCl
  • Na2 SO4

Answer: MgCl2

Q.24. Which of the following samples of water cannot be softened by zeolite process?

  • Water containing temporary hardness
  • Water containing permanent hardness
  • Water containing excess of alkalinity
  • Water containing excess of dissolved salts

Answer: Water containing excess of alkalinity

Q.25. The cation-exchange resins possess

  • Acidic groups
  • Basic groups
  • Amphoteric groups
  • None of these

Answer: Acidic groups

Q.26. Priming and foaming process in boiler-feed water is due to

  • The formation of air bubbles and production of wet steam
  • The formation of scales
  • The formation of sludges
  • None of these

Answer: The formation of air bubbles and production of wet steam

Q.27. The cation and anion resins are made up of the basic polymer unit of

  • Polyvinyl chloride
  • Poly acrylate
  • Poly styrene
  • Polybutadiene

Answer: Poly acrylate

Q.28. By ion-exchange process the hardness of water can be reduced up to

  • 0 ppm
  • 5 ppm
  • 10 ppm
  • 15 ppm

Answer: 0 ppm

Q.29. Boiler corrosion caused by using highly alkaline water in boiler is called

  • Corrosion
  • Boiler corrosion
  • Caustic embrittlement
  • Erosion

Answer: Caustic embrittlement

Q.30. Desalination is the process of removing

  • Common salt from sea water and making it potable
  • Hard salts from sea water
  • NaOH from hard water
  • None of the above

Answer: Common salt from sea water and making it potable

Q.31. An exhausted anion-exchange resin can be regenerated by treating it with

  • Conc. HCl solution
  • Conc. NaOH solution
  • Dilute brine solution
  • Conc. brine solution

Answer: Conc. NaOH solution

Q.32. Tannins and agar-agar are used for

  • Phosphate conditioning
  • Colloidal conditioning
  • Radioactive conditioning
  • Calgon conditioning

Answer: Colloidal conditioning

Q.33. Alum is commonly used in the treatment of municipal water for

  • Filteration
  • Sedimentation
  • Coagulation
  • Flocculant

Answer: Flocculant

Q.34. The chemical formula of alum is

  • K2 SO4 . Al2 (SO4)3 . 20H2O
  • KNO3 . Al2 (SO4)3 . 24 H2O
  • K2 SO4 . Al2 (SO4)3 . 24 H2O
  • K2 SO4 . Al2 (SO4)3 . 21 H2O

Answer: K2 SO4 . Al2 (SO4)3 . 24 H2O

Q.35. Liquid chlorine is most effective

  • Disinfectant
  • Coagulant
  • Flocculant
  • Sterilizing agent

Answer: Disinfectant

Q.36. The soft, loose, and slimy precipitate formed within the boiler is called

  • Scale
  • Sludge
  • Flocculant
  • Coagulant

Answer: Sludge

Q.37. In reverse osmosis (RO) the flow of solvent is due to

  • Potential gradient
  • Vapour pressure gradient
  • Concentration gradient
  • None of the above

Answer: Concentration gradient

Q.38. In the RO process, the membrane used is

  • Polysulfone
  • Polysulfone amide
  • Poly amide
  • All above

Answer: All above

Q.39. The chemical formula of bleaching powder is

  • Cl2
  • HOCl
  • NH2Cl
  • CaOCl2

Answer: CaOCl2

Q.40. The acid responsible for the disinfection of germs and bacteria is

  • HCl
  • HNO3
  • HOCl
  • H2 CO3

Answer: HOCl

Q.41. The amount of water available for human consumption is

  • 1%
  • 3%
  • 97%
  • 5%

Answer: 1%

Q.42. Water causes weathering of rocks due to the following phenomenon

  • Dissolution
  • Hydration
  • Hydrolysis
  • All of the above

Answer: All of the above

Q.43. The hardness of water is due to

  • K and Na salts
  • Salts of iron
  • Salts of Ca and Mg
  • SiO2

Answer: Salts of Ca and Mg

Q.44. Permanent hardness is due to

  • Carbonate of Ca
  • Bicarbonate of Mg
  • Chloride and sulphates of Ca and Mg
  • None of the above

Answer: Chloride and sulphates of Ca and Mg

Q.45. The most commonly used unit to express hardness is

  • Degree French
  • Degree Clarke
  • ppm
  • grains /gallon

Answer: ppm

Q.46. Scale in boilers are formed due to

  • Deposition of CaCO3
  • Deposition of CaSO4
  • Hydrolysis of magnesium salts
  • All of the above

Answer: All of the above

Q.47. Excess nitrate in drinking water causes

  • Anaemia
  • Blue baby syndrome
  • Irritation in skin
  • Mouth blisters

Answer: Blue baby syndrome

Q.48. The maximum permissible limit of fluoride in drinking water is

  • 1.5 ppm
  • 5 ppm
  • 3 ppm
  • 8 ppm

Answer: 1.5 ppm

Q.49. The Lime soda process uses

  • Ca(OH)2
  • Na2CO3
  • Both the above
  • None of the above

Answer: Both the above

Q.50. Which process is not used for the desalination of water

  • Reverse osmosis
  • Lime soda process
  • Electrodialysis
  • Flash evaporation

Answer: Lime soda process

Q.51. Residual hardness in the ion exchange process is

  • 10-15 ppm
  • 30-60 ppm
  • 0-2 ppm
  • 15-30 ppm

Answer: 0-2 ppm

Q.52. Alkalinity in water is due to

  • OH
  • CO32–
  • HCO3 
  • All of the above

Answer: All of the above

Q.53. Which is not used for disinfection of water

  • Chlorination
  • Electrodialysis
  • Ozonisation
  • Addition of KMnO4

Answer: Electrodialysis

Q.54. Dissolved oxygen in water is determined by

  • Mohr’s method
  • Gravimetric method
  • Winklers method or iodometric titration
  • EDTA method

Answer: Winklers method or iodometric titration

Q.55. Flash evaporation is a method of getting pure water from

  • Sea water
  • Industrial waste water
  • Domestic sewage
  • River water

Answer: Sea water

Q.56. Disinfection of water removes

  • Salts from water
  • Pathogenic bacteria from water
  • Dissolved oxygen from water
  • Hardness from water

Answer: Pathogenic bacteria from water

Q.57. The acceptable pH range for drinking water is

  • 7 to 8.5
  • 6 to 7
  • 6.5 to 9.2
  • 8 to 10

Answer: 7 to 8.5

Q.58. Which of the following is removed from water using the Nalgonda technique

  • Chlorine
  • Fluorine
  • Sulphates
  • Hardness in water

Answer: Fluorine

Q.59. The organic impurities from sewage are removed by

  • Preliminary treatment
  • Primary treatment
  • Secondary treatment
  • Tertiary treatment

Answer: Secondary treatment

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