Hardness of Water

Things to remember

• Hard water is a type of water which cannot form lather with soap and soft water is a type of water which can form lather with soap.
• Permanent hardness of water can be removed by treating it with washing soda.
•  One of the methods for removal of permanent hardness is Permutit process.
• Permanent hardness of water is due to the presence of salts such as magnesium chloride, magnesium sulphate, calcium chloride, etc.
• Temporary hardness of water is due to calcium bicarbonate and magnesium bicarbonate.