Hardness of Water MCQ Multiple Choice Questions Answers - Page 2 for Practice
31. The ion – exchange resins used for softening water are
Correct Answer is: Cross linked polymers with micro porous structure
32. The maximum desirable limits (as per BIS) of total hardness (as CaCO3) in drinking water is
Correct Answer is: 600 ppm
33. The method by which ions are pulled out of salt water by direct current, and employing thin and rigid membrane is called
Correct Answer is: Electrodialysis
34. The process of allowing water to stand undisturbed in big tanks for settling of the suspended particles due to force of gravity
Correct Answer is: sedimentation
35. The process of wet steam formation is called
Correct Answer is: priming
36. The purification of brackish water y reverse osmosis is also called as
Correct Answer is: Super – filtration
37. The soft, loose and slimy precipitate formed within the boiler is called
Correct Answer is: sludge
38. Ultraviolet rays are used in the treatment of water for
Correct Answer is: Sterilization.
39. Uneven deposition of turbines causes
Correct Answer is: Vibrational problems
40. When temporary hard water is boiled, one of the substance formed is
Correct Answer is: CaCO3
41. Which of the following chemical is sometimes added in the process of coagulation and flocculation.
Correct Answer is: Aluminum sulphate
42. Which of the following methods separates ionic and non – ionic impurities from water?
Correct Answer is: reverse osmosis
43. Which of the following physical method is used as germicidal in modern time for the treatment of drinking water?
Correct Answer is: UV radiation
44. Which of the following salts cause least hardness to water when converted to CaCO3 equivalents?
Correct Answer is: 19 mg of CaSO4
45. Which of the following substances are commonly used in a filter?
Correct Answer is: both a & b
46. Zeolite softening process removes
Correct Answer is: Both temporary and permanent hardness of water
47. Zeolite used in zeolite softening process for the treatment of hard water gets exhausted after certain time of usage but can be regenerated by flushing it with
