Some Impotent Trams About Water Which Is Used In Textile Wet Processing?

##Why water is called universal solvent?

Water is called universal solvent, because the solvency power of water is very high & most of the solute of this world is easily dissolved in the water.

##What do you mean by water hardness?

Hardness is a term applied to water denoting a measurement of its pH & metal salt content. The presence of Ca & Mg salt i.e. Bi-Carbonates, Sulfates, Chlorides in water is called causes of hardness of water. The water which contains these salts is called hard water. Hard water does not easily form lather with soap as the salt of Ca & Mg react with soap to form insoluble organic salts.

CaSO4 + 2 RCOONa →  (RCOO)2Ca ↓ + Na2SO4.

MgSO4 + 2 RCOONa → (RCOO)2Mg ↓ + Na2SO4.

##State different types of water hardness?

Water hardness may be classified into following two types-

1) TEMPORARY HARDNESS:

Temporary hardness is due to the presence of Bi-Carbonates of Ca & Mg. this type of hardness is called temporary hardness, because, it can be removed by easy means like boiling. When temporary hard water is boiled, the Carbonates decompose with liberation of CO2 & precipitation of the insoluble Carbonates which are reformed.

Ca(HCO3)2 ∆→ CaCO3↓  + CO2   + H2O Mg(HCO3)2 ∆→ MgCO3 ↓ + CO2   + H2O

2) PERMANENT HARDNESS:

It is due to the presence of Sulfates, Chlorides of Ca & Mg. this type of hard water is called permanent hardness. These salts do not decompose on boiling. So, permanent hardness cannot be removed.

##Write down the name of mineral metallic salts which is responsible for water hardness?

The name of mineral metallic salts which is responsible for water hardness-

1. Ca(OH)2;    

2. Mg(HCO3)2;

3. Al(HCO3)2;

4. Fe(HCO3)2;       

5. CaSO4;    

6. MgSO4;

7. Al2(SO4)3;         

8. FeSO4;    

9. CaCl2;

10. MgCl2;   

11. AlCl2;      

12. FeCl2.

##Why soap does not create foam easily with hard water? Explain with reaction?

Soap does not create foam easily with hard water as the salt of Ca & Mg react with soap to form insoluble organic salts.

CaSO4 + 2 RCOONa →  (RCOO)2Ca ↓ + Na2SO4.

MgSO4 + 2 RCOONa → (RCOO)2Mg ↓ + Na2SO4.