Question

A water sample contains fMgSO What is . 68 mofCaSO4and60ppmo 4· . Mg(HC03 )2 , PP 1 ? (Atomic weights of calcmm, the hardness of the water sa~:s ctively 40, 24 and 32). magnesium and sulphur are p (SCRA
A. 50ppm
B. 100ppm
C. 150ppm
D. 200ppm

Answer 1

Correct Answer - D
(i) `Ca(HCO_(3))_(2) -= CaCO_(3)`
"162 ppm" = "100 pmm"
`therefore "81 ppm" -= "50 pmm"`
(ii) `Mg(HCO_(3))_(2) -= CaCO_(3)`
`"146 ppm" -= "100ppm"`
`therefore" 68 ppm"-= "50pmm"`
(iii) `CaSO_(4) -= CaCO_(3)`
"136 ppm" -="100ppm"`
` therefore "68pmm"-= "50ppm"`
(iv) `MgSO_(4) -= CaCO_(3)`
`"120 ppm" -= "100 ppm"`
`therefore " 60 ppm" -= "50 pmm"`
Total degre of hardness of water `= 50 xx 4 = 200 "ppm"`