how to calculat temporary hardness water and permanent hardness of water and total hardness and normality can anyone help me to find solution

Question

how to find hardness of water and normality in calculation

Answer 1

Permanent hardness (total permanent hardness) is the calcium hardness plus the magnesium hardness and these are given as calcium carbonate (CaCO₃) equivalents. There are several ways that are used to calculate this.  The values are generally given as ppm or as mg/liter (same thing). One way is as follows:

 

 The molar mass of CaCO₃ is 100, and that of Ca²⁺ is 40, and that of Mg²⁺ is 24.  Thus, for Ca²⁺ you have 100/40 = 2.5 and for Mg²⁺ you have 100/24 = 4.2.

Total Permanent Hardnes = 2.5[Ca²⁺] + 4.2[Mg²⁺].

 

Temporary hardness is the Ca and Mg present as their bicarbonate salts, i.e. Ca(HCO₃)₂ and Mg(HCO₃)₂.  This usually comes from boiling the water.  The reaction for Ca would be Ca(HCO3)2 ==> CO₂(g) + H2O(l) + CaCO₃(s)

 

As far as normality is concerned, that term is hardly used anymore, but it is the equivalents/liter instead of moles/liter (M). So, for both Ca²⁺ and Mg²⁺, the normality will be 2x the molarity.