Hard and soft water

•Hard water contains dissolved compounds,calcium or magnesium ions –The compounds are dissolved when water comes into contact with rocks •There are two types of hard water –Permanent hard water remains hard when it is boiled –Temporary hard water is softened by boiling –Temporary hard water contains hydrogencarbonateions (HCO3-) that decompose on heating to produce carbonate ions , react with calcium and magnesium ions to form precipitates. •Soft water readily forms lather with soap •Hard water reacts with soap to form scum and so more soap is needed to form lather –Soapless detergents do not form scum •hard water can increasecosts, temporary hard water heated produce scale that reduces the efficiency of heating systems and kettles •Hard water benefits,  calcium compounds are good for bones and teeth and also help to reduceheart disease