The softener then required 400 litres of sodium chloride solution containing 100 g/L of NaCl for regeneration. Calculate the hardness of the water sample

FE > Semester 1 > Applied Chemistry 1

Marks : 08

Years : DEC 2015

$$100g \text { of } NaCl → 1 \text { litre } $$

$1g = 1000 mg \\ 10^2×10^3 mg \text { of } NaCl→1 \text { litre } \space\space\space 10^2 g \\ 10^5 mg \text { of } Nacl→1 \text { litre } $

400 litres solution cxontains $-\gt 400 \times 10^5 mg \text { of } NaCl$

Now,

$CaCO_3$ equivalent $= 400 \times 10^5 \times 100/ (2 \times 58.5) \\ = 341.88 \times 10^5 mg \text { of } CaCO_3$ equivalent

$1 \text { litre } = 341.88 \times 10^5 ppm \\ 10^4 \text { litre } = x \\ X = 341.88 \times 10^5 \times 10^4$

Hardness of water sample $= 341.88 \times 10^9 ppm$