Unit 1 - Practice Quiz

1 Which of the following pairs of ions are primarily responsible for the hardness of water?

2 Temporary hardness in water is caused by the presence of which of the following salts?

3 Which relationship correctly correlates the units of hardness?

4 Why is Calcium Carbonate () chosen as the standard for expressing hardness equivalents?

5 In the EDTA method for hardness determination, which indicator is used?

6 What is the pH range maintained during the EDTA titration for hardness determination?

7 What is the color change observed at the end point of the EDTA titration?

8 Calculate the calcium carbonate equivalent of 136 mg/L of present in a water sample. (Atomic wts: Ca=40, S=32, O=16)

9 Which of the following ions is NOT responsible for the alkalinity of water?

10 If Phenolphthalein alkalinity () is zero in a water sample, the alkalinity is due to:

11 When (where is Phenolphthalein alkalinity and is Methyl Orange alkalinity), the alkalinity is caused by:

12 Which combination of ions cannot coexist in water regarding alkalinity?

13 Which defect in boilers is caused by the formation of a soft, loose, and slimy precipitate?

14 Scales in boilers are primarily composed of:

15 Caustic embrittlement in boilers is caused by:

16 Which chemical is added to boiler water to prevent caustic embrittlement?

17 The phenomenon of producing wet steam (steam containing water droplets) is known as:

18 Dissolved oxygen in boiler feed water causes:

19 In the Lime-Soda process, Lime () is NOT required for the removal of:

20 Why is sodium aluminate () used in the Lime-Soda process?

21 The Zeolite process (Permutit process) removes hardness by exchanging:

22 Exhausted zeolite is regenerated using a 10% solution of:

23 One major disadvantage of the Zeolite process is:

24 Which process produces demineralized (deionized) water?

25 In the Ion Exchange process, the Cation exchange resin () is regenerated using:

26 What functional group is typically present in Anion exchange resins?

27 Calgon conditioning prevents scale formation by forming:

28 A water sample contains 73 mg/L of . What is its hardness in terms of equivalent? (Mol wt of )

29 During the calculation of Lime requirements, the amount of Lime needed for is multiplied by:

30 Which component does NOT require Soda () during the calculation for softening?

31 Reverse Osmosis (RO) takes place when the applied pressure is:

32 Which semi-permeable membrane is commonly used in Reverse Osmosis?

33 Electrodialysis involves the migration of ions towards electrodes through:

34 Desalination refers to the removal of:

35 The chemical formula for Bleaching Powder is:

36 The most effective disinfecting form of chlorine in water is:

37 What is 'Breakpoint Chlorination'?

38 Sterilization of water using Ozone () is advantageous because:

39 According to BIS (IS 10500:2012) and WHO standards, the desirable limit for pH in drinking water is:

40 The maximum permissible limit for Total Hardness (as ) in drinking water in the absence of an alternate source is:

41 Excess Fluoride in drinking water (> 1.5 mg/L) causes:

42 100 mL of water required 10 mL of 0.01M EDTA for titration. What is the total hardness?

43 Boiler corrosion due to acidity is controlled by adding:

44 What is the function of Sodium Sulfite () or Hydrazine () in boiler feed water treatment?

45 Which of the following is a unit of hardness used in France?

46 In the determination of alkalinity, if the volume of acid used for Phenolphthalein endpoint is and total acid for Methyl Orange endpoint is , and , then:

47 Hard water is NOT suitable for washing clothes because:

48 A water sample contains . On boiling this water, the hardness:

49 Colloidal conditioning involves adding substances like kerosene, tannin, or agar-agar to:

50 In the standard EDTA solution preparation, why is Magnesium added to the EDTA solution sometimes?