Causes of hardness

Causes of hardness of water 

Various salts get dissolved in natural water when it passes over rocks or through the several underlying layers of earth 

The bicarbonates ,chlorides and sulphates of calcium and magnessium are most common salts dissolved in water which makes it hard thus hard water is defined that the water which contain the impurities of bicarbonates, chlorides and sulphates of calcium and magnessium which prevents water from leathering and thats why the hard water never produces leather with the soap solution 

When the water containing calcium and magnessium ion treated with soap (sodium and potassium salts of higher fatty acids like oleic ,palmatic, steric)

So that it does not produces lathe with the soap solution but it produces a white precipitates of the Ca+2 or Mg+2 salts of the corresponding fatty acid 

☆      2C 15 H 31 COONa (sodium                         palmitate) + CaCl2 ---------> (C 15 H             31 COO)2 Ca (calcium palmitate as           a ppt.) + 2NaCl 

☆     sodium palmitate + magnessium                chloride ---------> magnesium                        palmitate (ppt.) + sodium chloride 

☆    sodium stearate (soluble in water )            + calcium chloride ----------> calcium          stearate (ppt.) + sodium chloride 

☆    sodium stearate (soluble in water) +          magnessium chloride ------->                        magnesium stearate (ppt.) + sodium         chloride 

Thats why the leather is formed until all the Ca+2 or Mg+2 ions get precipitated completely 

So that now we can say that the hardness of water can be understan as the soap consuming capacity of the water sample hence, the hard water is not suitable for washing purposes because too much salt get west 

Hard water 

Thankyou
 By :- ADARSH GUPTA