Question

calculate the hardness of water sample whose 10ml requires 20 ml of EDTA 20ml of calcium carbonate solution whose strength is equivalent of 1.5 g of calcium carbonate per litre required 30 ml of EDTA solution​

Answer 1

Answer:

The standard water contains 1.5 g of CaCO3/l.

1000 ml of standard hard water (SHW), therefore, contain 15,00 mg of CaCO3.

1 ml of standard water = 15,00/1000 = 1.5 mg of CaCO3 equivalent.

10 ml of EDTA solution = 10 ml of SHW contains

=> 10* 1.5 = 15 mg of CaCO3 equivalent

1ml o EDTA Solution = 15 / 10 = 1.5 mg of CaCo3 equivalent

Calculation of hardness of water:

100 ml of water 30 ml of EDTA solution

30 * 1.5 = 45 mg of CaCO3 equivalent

1000 ml of water = 450 mg of CaCO3 equivalent

Hardness of water = 450 mg / l