# Calculate the total hardness in ppm in given water sample.: 50ml of standard hard water , containing 1mg pure CaCO3 per ml consumed 20ml EDTA solution. - Applied Chemistry 1

Numerical

Calculate the total hardness in ppm in given water sample.
: 50ml of standard hard water , containing 1mg pure CaCO3 per ml consumed 20ml EDTA solution.
: 50ml of water sample consumed 30ml EDTA solution using EBT indicator.

#### Solution

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 =  50/20  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 xx 30 ) /50
= 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.

Concept: Hardness of Water
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