Permanent Hardness

Explanation

Temporary hardness of water is casued due to the presence of bicarbonates of calcium and magnesium, i.e., `Ca(HCO_(3))_(2)` and `Mg(HCO_(3))_(2)`, while permeanent hardnessof water is due to the presence of soluble chlorides and sulphates of calcuim and magnesium, i.e., `CaCl_(2)MgCL_(2)`,`CaSO_(4)` and `MgSO_(4)`.