What are the types of hardness present in water

☆  Types of hardness

 

Hardness of water is of two types temporary hardness or parmanent hardness not  a days these hardness is determined by the term alkaline and non-alkaline hardness so that these term is used at the place of temporary or parmanent hardness 

It is also expressed as carbonate or non- carbonate hardness 

1. Temporary hardness or carbonate or alkaline hardness :- 

The temporary hardness in water mainly cause by the presence of soluble bicarbonates of calcium and magnessium in water 

By the boilling of this water the temporary hardness of the water could be removed easily 

When dissolved bicarbonates are dicomposed yielding insoluble carbonates and hydroxide which are deposited as a crust at the bottom of the vessel 

*  Calcium bicarbonate -- (heat)---------->      calcium carbonate + water + carbon        dioxide 

*  magnessium bicarbonates ---(heat)-->

    magnessium hydroxide  (insoluble )        +  carbon dioxide 

These insoluble carbonates and hydroxides are further removed by filteration

And the salts of bicarbonates , carbonates etc. are responsible for temporary hardness 

Due to presence of bicarbonates and hydroxides of the hardness causing metal ions it is termed as alkaline hardness and which can be determined by titeration with HCl using methyl orange 

2. Permanent hardness :- 

It is caused due to the presence of sulphates ,chlorides and nitrates of calcium ,magnessium, iron and other heavy metals 

It can't be removed by simple boilling but it can be removed by using some chemical method 

And this kind of hardness is also known as non-alkali hardness

The causing salts are chlorides of calcium and magnessium, simulates of calcium and magnessium, nitrates of calcium and magnessium,  etc. These salts are responsible for permanent hardness in water 

BY :- ADARSH GUPTA