100 mL of tap water containing `Ca(HCO_(3))_(2)` was titrated with `N//50HCl` with methyl orange as indicator. If 30 mL of `HCl` were required, calculate the temporary hardness as parts of `CaCO_(3)` per `10^(6)` parts of water.

Options

A. 150 ppm
B. 300 ppm
C. 450 ppm
D. 600 ppm

Answer

B

Explanation

`"30 mL N/50 HCl "-= "30 mL N/50 "Ca(HCO_(3))_(2)`
`-=" 30 mL N/50 "CaCO_(3)-="100 mL tap water"`
`"Mass of "CaCO_(3)" in 100 mL tap water"`
`=(ExxNxxN)/(1000)=(50xx30)/(50xx1000)=0.03g`
`rArr" hardness = 300 ppm"`