Water that contains a highconcentration of magnesium and calciumions
Hard water forms in naturalareas where water flows over rocks that contain magnesium and calcium e.g Gypsum and limestone
Calcium carbonate getting into water
Calcium carbonate is insoluble
The calcium reacts with dissolvedcarbondioxide and water to form solublecalciumhydrogencarbonate
CaCO3 (s) + H2O (l) + CO2 (g) = Ca(HCO3)2 (ag)
It is then carried in waters which later may be deposited in reservoirs
Disadvantages to hard water
Hard water makes soap ineffective. For soap to be effective, it has to from a lather which helps to wash away grease and dirt in water. The magnesium and calcium ions interfere with this process. They react with the salt to form
Leaves deposits such as scum or calcium carbonate (Limescale)
Stearate ions
A negative ion
Formed from salt of fatty acid. Found in soap
How is hard water measured?
By the amount of soap needed to form a lather
The moresoap, the harder the water
Advantages of hard water
Calcium is good for bones and teeth
Reduction of the chance/incidence of cardiovasculardisease
