DEFINE & Calcification of ACID? | THE PROPERTIES &USES OF ACID IN WET PROCESSING OF TEXTILE?

DEFINE ACID?

The compound containing hydrogen atom which are replaced by metal or metal likeactivated radical & produce salt & water is called acid.

On the other hand, we can say, the hydrogen containing compound which are ionized in water & produce hydrogen ion as a positive ion is known as acid.

Example: H2SO4, HCl, HNO3 etc.

Calcification of ACID?

A)       On the basis of constitution:

i)         HYDRO ACID: The acids which contain Hydrogen atom are called hydro acid. Example: HCl, HCN etc.

ii)        OXI ACID: The acids which contain oxygen & Hydrogen atom are called oxi acids.

Example: H2SO4, HNO3 etc.

B)       On the basis of origin:

i)         ORGANIC: The acids which are obtained from animals & vegetables are called organic acids. Example: acetic acid, formic acid etc.

ii)        INORGANIC: The acids which are obtained from mineral are called inorganic acids. Example: HCl, H2SO4 etc.

C)       On the basis of strength:

i)         STRONG ACID: The acids which are fully ionized in water & produce large amount of H+ are called strong acid. Example: H2SO4, HCl etc.

ii)        WEAK ACID: The acids which are partially ionized in water & produce large amount of H+ are called weak acid. Example: HCOOH.

D)       On the basis of alkalinity:

i)         MONO ALKALINE ACID: The acid which are contains only one Hydrogen atom is called mono alkaline acid. Example: HCl, HCN etc.

ii)        DI-ALKALINE ACID: The acid which contains two replaceable Hydrogen atom is called di-alkaline acid. Example: H2SO4.

iii)       TRI-ALKALINE ACID: The acid which contains three replaceable Hydrogen atom is called tri-alkaline acid. Example: H3PO4.

THE PROPERTIES OF ACID?

Properties:

1.Acid ionized in water & produce hydrogen ion.

HCl  = H + + Cl -

H2SO4 = 2 H+ + SO4-

2. In the presence of hydrogen ion, acid changes the color of litmus from blue to red. Blue litmus + H+ = red litmus.

3.Acid reacts with alkali & produce salt & water.

HCl + NaOH = NaCl + H2O.

NaOH + H2SO4 = NaHSO4 + H2O

NaHSO4 + NaOH = Na2SO4 + H2O.

4.The taste of acid is sour.

5.Acid reacts with strong metal such as Mg, Al, Zn & produce Hydrogen gas.

2 HCl + Mg = MgCl2 = MgCl2 + H2.

THE USES OF ACID IN WET PROCESSING OF TEXTILE?

• Acid is used in scouring process (HCl).
• H2SO4 is used to soften hard water in case of demineralization or ion exchange process.
• HCl is used in carbonizing of wool.
• H2SO4 is used in spgn process of viscose rayon.
• Acids are used for dyeing of protein fiber with acid dye.
• HCl is used to dissolve the di-azo compound.
• H2SO4 is used for fermentation.
• H2SO4 (conc.) is used for neutralizing mercerized product.
• Acetic or formic acid is used to adjust pH of dye bath.
• Acids are used for washing purpose.
• H2SO4 or HCl is used for acid steeping.