Temporary Hardness of Water:
The presence of magnesium and calcium carbonates in water makes it temporarily hard. In this case, the hardness in water can be removed by boiling the water.
When we boil water the soluble salts of Mg(HCO3)2 is converted to Mg(OH)2 which is insoluble and hence gets precipitated and is removed. After filtration, the water we get is soft water.
Permanent Hardness of Water:
When the soluble salts of magnesium and calcium are present in the form of chlorides and sulphides in water, we call it permanent hardness because this hardness cannot be removed by boiling.
We can remove this hardness by treating the water with washing soda. Insoluble carbonates are formed when washing soda reacts with the sulphide and chloride salts of magnesium and calcium and thus, hard water is converted to soft water.
The presence of magnesium and calcium carbonates in water makes it temporarily hard. In this case, the hardness in water can be removed by boiling the water.
When we boil water the soluble salts of Mg(HCO3)2 is converted to Mg(OH)2 which is insoluble and hence gets precipitated and is removed. After filtration, the water we get is soft water.
Permanent Hardness of Water:
When the soluble salts of magnesium and calcium are present in the form of chlorides and sulphides in water, we call it permanent hardness because this hardness cannot be removed by boiling.
We can remove this hardness by treating the water with washing soda. Insoluble carbonates are formed when washing soda reacts with the sulphide and chloride salts of magnesium and calcium and thus, hard water is converted to soft water.