* Temporary Hardness: This is caused by the presence of dissolved bicarbonates of calcium and magnesium. The main culprit here is calcium bicarbonate (Ca(HCO3)2) and magnesium bicarbonate (Mg(HCO3)2). These salts are dissolved in water due to the presence of carbon dioxide, and they can be removed by boiling the water. This process drives off the dissolved CO2, causing the bicarbonates to decompose and form insoluble carbonates, which precipitate out of the solution.
* Permanent Hardness: This is caused by dissolved chlorides and sulfates of calcium and magnesium. Examples include calcium chloride (CaCl2), calcium sulfate (CaSO4), magnesium chloride (MgCl2), and magnesium sulfate (MgSO4). These salts are not affected by boiling and remain dissolved in the water, making it permanently hard.
In summary:
* Temporary Hardness is caused by bicarbonates of calcium and magnesium, which can be removed by boiling.
* Permanent Hardness is caused by chlorides and sulfates of calcium and magnesium, which are not affected by boiling.
