Question
100 ml of tap water containing Ca(HCO_3)_2 was titrated with N/50 HCl with methyl orange as indicator. If 30 ml of HCl was required, calculate the temporary hardness as parts of CaO_3 per 10^{6 }parts of water. (1) 150 ppm (2) 600 ppm (3) 450 ppm (4) 300 ppm