50 mL of standard hard water containing 1 mg of pure CaCO3 per mL consumed 20 mL of EDTA. 50 mL of water sample consumed 25 mL of same EDTA using EBT. Calculate the total hardness of water sample in ppm.
Answers
Answer:
1 ml SHW = 1 mg of CaC03 eq.
∴ 50ml SHW = 50 mg of CaC03 eq .
50 ml of SHW = 20 ml of EDTA solution.
20 ml of EDTA = 50 mg of CaC03 eq.
∴ 1 ml of EDTA =
5020 mg of CaC03 eq .
= 2.5 mg of CaC03 eq.
50 ml of water sample = 30 ml of EDTA solution.
∴ 1000 ml of water sample =
1000×3050
= 600 ml of EDTA solution
1 ml of EDTA = 2.5 mg of CaC03 eq.
∴ 600 ml of EDTA = 2.5x 600
= 1500 mg of CaC03 eq.
∴ Total hardness of = 1500 mg/L
water sample = 1500ppm.