31.
In sugar solution,

32.
The metallic constituents of hard water are :

33.
Potassium Permanganate is used for purifying drinking water, because________

35.
Hardness of the water is commonly measured in terms of

36.
Maximum permissible concentration of copper in drinking water in mg/L is

37.
The amount of chlorine available in water after disinfection is called as

38.
Maximum permissible concentration of total hardness in drinking water is

39.
Which one of the following is extensively used for sterilizing water ?

40.
Assertion (A) : Synthetic detergents can lather when in hard water.
Reason (R) : Synthetic detergents form soluble calcium and magnesium salts with hard water.