20 ml of std water containing 1 g of pure CaCO3 per lit consumed 25 ml of EDTA. 100 ml of water sample consumed 18 ml of EDTA using EBT as indicator. While same water sample requires 12 ml of EDTA solution Calculate carbonate and non-carbonate hardness of water

1ml of std water = 1mg of KOH 20 ml of std water = 20 mg of CaCO3 25 ml of std water = 20 mg of CaCO3

1 mi of EDTA = 20 /25 mg of CaCO3

= 0.8 mg of CaCO3

1000 ml of H2O = 1000/100 X 18X 0.8

Total hardness = 144 ppm

1000 ml of H2O = 1000/100 X 12X 0.8

Permanent hardness = 96 ppm

Temporary harness = Total hardness – permanent hardness

Temporary harness = 144 – 96

Temporary harness = 48 ppm