Hardness of Water Multiple Choice Questions and Answers

41. Which of the following chemical is sometimes added in the process of coagulation and flocculation.

1. Aluminum sulphate
2. Aluminium oxide
3. Calcium chloride
4. none of these

42. Which of the following methods separates ionic and non – ionic impurities from water?

1. Electrodialysis
2. deionization
3. reverse osmosis
4. zeolite process

43. Which of the following physical method is used as germicidal in modern time for the treatment of drinking water?

1. Chlorination
2. Treating with Potassium permanganate
3. UV radiation
4. Treating with Bleaching powder

44. Which of the following salts cause least hardness to water when converted to CaCO₃ equivalents?

1. 10 mg of CaCO₃
2. 19 mg of CaSO₄
3. 10 mg of MgCl₂
4. 10 mg of CaCl₂

45. Which of the following substances are commonly used in a filter?

1. Charcoal
2. Sand
3. both a & b
4. Aluminium Chloride

46. Zeolite softening process removes

1. Only temporary hardness of water
2. Only permanent hardness of water
3. Both temporary and permanent hardness of water
4. The dissolved gases in permanent hard 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

1. 10% calcium chloride solution
2. 10% Magnesium Chloride solution
3. 10% Magnesium sulphate solution
4. 10% sodium chloride solution