Hardness Of Water

Characteristics

Soft Water:

• Lathers well with soap

Hard Water:

• Scum forms unless a soapless detergent is used
• Dissolved calcium and magnesium ions react with soap to form scum (insoluble)
• More soap required to form a lather -> more expensive
• Forms scale when heated (Calcium Carbonate) on the insides of pipes/kettles/etc. 
  • Badly scaled boilers and pipes mean less efficient heating systems
  • Need replacing so scale doesn't block pipes -> costs money
  • Scale is a thermal insulator -> Kettle takes longer to boil so is less efficient. 

Cause of Hard Water:

• Contain Ca2+ and Mg2+ ions
• When rain falls on rocks like limestone, chalk and gypsum, compounds like Magnesium sulfate and…