hard and soft water

soft water produces lots of lather

hard water produces less lather (difficult to produce)

calcium ions in limestone and magnesium in gypsum make water hard, as the water (H20) runs over the limestone or gypsum the calcium or magnesium dissolves in the water

scum:

hard water leaves scum in baths and sinks it is formed when the soap reacts with ions in the hard water

• soap reacts with calium and magnesium ions
• unsoluble salts (calcium stearateprecipitate) are formed with appear with scum

limscale:

• when hard water is heated
• common in kettles and washing macheines

advantages

• helps reduce heart illness
• calcium in hard water is good for childrens bones
• some brewers like using hard water for making beer
• some people prefer the taste

disadvantages

• difficult to form lather
• dcum forms a reaction and wastes soap
• limescale forms a hard rust on kettles and wastes energy when it is used
• hot water pipes 'fur up' inside. the scale blocks up the pipes

• boilling removes hardness and makes it soft.
• adding washing soda

ion exchange collum:

often used in dishwashers or plumbed into water systems to continuosly soften water. Resin beads have sodium ios attatched to them. as the hard water passes through the collum, the calcium and magnesium swap places with the sodium ions. The calcium and agnesium ions are left attatched to the resin beads while the water leaving the collum contains ore soium ions

and disadvantage is that the resin beads will have to be changed