The hardness of water due to `HCO_3` is `122 p p m`. Select the correct statement(s).

Options

A. The hardness of water in terms of `CaCO_(3)` is 200 ppm.
B. The hardness of water in terms of `CaCO_(3)` is 100 ppm.
C. The hardness of water in terms of `CaCl_(2)` is 222 ppm.
D. The hardness of water in terms of `MgCl_(2)` is 95 ppm.

Answer

B, D

Explanation

Since 2 " mol of "`HCO_(3)^(ɵ)` is present. So there should be one mole each of `CaCO_(3)`, `CaCl_(2)` and `MgCl_(2)` to have equal hardness.
`thereforeMw of HCO_(3)^(ɵ)=61`,
`ppm of HCO_(3)^(ɵ)=61xx2=122 g` in `10^(6) mL H_(2)O`
`[Mw of CaCO_(3)=100,Mw of CaCl_(2)=111,Mw of MgCl_(2)=95g mol^(-1)]`
`1 " mol of "CaCO_(3)-=100ppm`
`1 " mol of "CaCl_(2)=111 ppm`
`1 " mol of "MgCl_(2)=95 ppm`
Hence, answer is (b) and (d).