how to find hardness of water and normality in calculation
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.