Question

Explain how temporary and permanent hardness of water is removed??

Answer 1

Hard water contains dissolved magnesium and calcium ions. These make it more difficult for the water to form a lather with soap. Temporary hardnessis caused by dissolved calcium hydrogencarbonate (which is removed by boiling). Permanent hardness is caused by dissolved calcium sulfate (which is not removed by boiling).

Answer 2

Hard water contains dissolved magnesium and calcium ions. These make it more difficult for the water to form a lather with soap. Temporary hardnessis caused by dissolved calcium hydrogencarbonate (which is removed by boiling). Permanent hardness is caused by dissolved calcium sulfate (which is not removed by boiling).

Permanent hardness is hardness (mineral content) that cannot be removed by boiling. When this is the case, it is usually caused by the presence of calcium sulfate and/or magnesium sulfates in the water, which do not precipitate out as the temperature increases. Ions causing permanent hardness of water can be removed using a water softener, or ion exchange column.

Total Permanent Hardness = Calcium Hardness + Magnesium Hardness

The calcium and magnesium hardness is the concentration of calcium and magnesium ions expressed as equivalent of calcium carbonate.

Total permanent water hardness expressed as equivalent of CaCO3 can be calculated with the following formula: Total Permanent Hardness (CaCO3) = 2.5(Ca2+) + 4.1(Mg2+)