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

Options

A. The hardness of water in terms of `CaCO_(3)` is `200 p p m`
B. The hardness of water in terms of `CaCO_(3)` is `100 p p m`
C. The hardness of water in terms of `CaCO_(3)` is `22 p p m`
D. The hardness of water in terms of `CaCO_(3)` is `95 p p m`

Answer

B, D

Explanation

Since `2` mol of `HCO_(3)^(ɵ)` is present, there should be one mole each of `CaCO_(3), CaCl_(2)` and `MgCl_(2)` to have equal hardness.
`:. Mw of HCO_(3)^(ɵ)= 61`
`p p m of HCO_(3)^(ɵ)=61xx2=122g` in `10^(6) mL H_(2)O`
`[MW of CaCO_(3)=100,MW of CaCl_(2)=111, MW of MgCl_(2)=95 g mol^(-1)]`
`1` mol of `CaCO_(3)=100 p p m`
`1` mol of `CaCl_(2)=111 p p m`
`1` mol of `MgCl_(2)=95 p p m`
hence , (b) and (d) are correct option