Who is x. `(HCOO)_2Ca rarrX+ CaCO_3`

Temporary hardness is due to bicarbonates of Mg^(2+) and Ca^(2+) . It is removed by addition of CaO as follows: Ca(HCO_(3))_(2) + Cao rArr 2CaCO_(3) + H_(2)O Mass of CaO required to precipitate 2g CaCO_(3) is:

In Clark's method which of the following is removed by using Ca(OH)_(2) a) CaCO_(3) ,b) Ca(HCO_(3))_(2) ,c) Ca(OH)_(2) ,d) NaOH

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 were required, calculate the temporary hardness as parts of CaCO_3 per 10^6 parts of water.