Hard and soft water

Reacting with soap

• Soft water + soap -> lather (easily)
• Hard water + soap -> scum
• This means more soap is needed to make hard water into lather.
• Soapless detergents do not form scum.

Hard water

• Hard water - dissolved compounds usually calcium or magnesium.
• These compounds dissolve when water comes into contact with rocks.

Two types of hard water:

• Permanent hard water - remains hard when boiled.
• Temporary hard water - softened by boiling.
• Temporary hard water contains hydrogencarbonate ions (HCO3-) that decomposes…