The hardness due to 1.62 ppm of Ca(HCO3)2 will be A. 1 ppm D. 100 ppm B. 0.1 ppm C. 10 ppm
Answers
Answer:
We can calculate the hardness of given water sample as:
(i) Ca(HCO
3
)
2
≡CaCO
3
162ppm≡100ppm
∴81ppm≡50ppm
(ii) Mg(HCO
3
)
2
≡CaCO
3
146 ppm ≡ 100 ppm
∴73ppm≡50ppm
(iii) CaSO
4
≡CaCO
3
136ppm≡100ppm
∴68ppm≡50ppm
(iv) MgSO
4
≡CaCO
3
120ppm≡100ppm
∴60ppm≡50ppm
The hardness is most commonly expressed as milligrams of calcium carbonate equivalent per litre. Calcium carbonate is the compound in hard water that causes limescale build-up. Soft water generally has less than 50 ppm of calcium carbonate, and hard water has over 200 ppm.
Total degree of hardness of water =50×4=200ppm
D. 100 ppm
The hardness is most commonly expressed as milligrams of calcium carbonate equivalent per litre. Calcium carbonate is the compound in hard water that causes limescale build-up. Soft water generally has less than 50 ppm of calcium carbonate, and hard water has over 200 ppm.