Question

What is acid?

What are it's types ?

Explain in brief ...

Answer 1

acid:- 
1) they release H+ ions in aq. solution.

2) they are sour in taste.

3) acids are corrosive.

4) they react with bases to form salt and water.

5) they turn blue litmus paper red.


types of acids:-
1) MINERAL ACIDS or INORGANIC ACIDS:-
a) they isolate into ions.
b) show high conductivity.
c) eg:- H₂SO₄, HCl etc.

2) CARBOXYLIC ACIDS:-
a) it includes amino acids and acetic acid.
b) they are more acidic.
c) eg- methanoic acid, ethanoic acid etc.

3) SULFONIC ACID:-
a) derived from sulphuric acid.
b) it is the strongest oranc acids.
c) eg- CH₃SO₃H (methane sulfonic acid).

4) Nucleic acids:-
a) they are found in nuclei of all living cells.
b) they are long-chain polymers.
c) eg- DNA (deoxyribonucleic acid), RNA (ribonucleic acid).

Answer 2

Acids are those substances which have a sour taste. 

The sour taste in fruits like orange, lemon etc. is due to the presence of an acid in it.

Properties of Acids:-
1. Acids have a sour taste.

2. Acids turn blue litmus to red.

3. Acid solutions conduct electricity. 

4. Acid reacts with metals to produce hydrogen gas. 

Metal + Acids => Hydrogen gas

For example: -

Zn + H2SO4 ---------> ZnSO4 + H2

5. Acids react with metal carbonates to form carbon dioxide gas. 

Metal carbonate + Acid -----------> Salt + carbon diaxide + water

For example:- 

NaHCO3 + HCL ---------> NaCl + CO2 + H2O

6. Acids react the base or alkali to form salt and water.

Acid + base => salt + water 

HCl + NaOH ---> NaCL + H2O 

7. Acid react with metal oxides to form salt and water.
metal oxide + acid => salt + water

for example:-
CuO + 2HCl => CuCl2 + H2O

8. Acids have corrosive nature.
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Types of acids:-

Organic acids
The acids present in plant material are called organic acids. Organic acids are weak acids. It is not harmful to eat or drink substances containing naturally occurring acids in them.

Examples of organic acids:- 

Lactic acid, Citric acid, Acetic acid (or ethanoic), Tartaric acids, oxalic acid and formic acid (or methanoic). 

Vinegar ----> Acetic acid
Curds ----> Lactic acid
Oranged----> Citric acid
Tamarind ------> Tartaric acid
Ant sting -----> Formic acid
Tomatoes -----> Oxalic acid


Mineral acids:-
Man-made acids are known as mineral acids. 

These acids are very dangerous. They can burn our skin and clothes. Acids are generally mixed up with water to dilute them, such acids are called dilute acids.  

Three most common examples of mineral acids:-
---Hydrochloric acid
---Nitric acid
---Sulphuric acids.

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Acids are strong and weak.

Strong acids : - Acids which dissociate almost fully in the aqueous olution to produce a large amount of H+ ions. All the mineral acids are strong acids.

For example:- 

HNO3 + water -----> H+ (aq) + Cl- (aq)

HCL + Water --------> H+ (aq) + NO-3 (aq) 


Weak acid:- Acids which dissociate only partially in the aqueous solution to produce a small amount of H+ ions. 


For example:-

H2CO3 + water ------> 2H (aq) + CO²- 3 (aq)

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Concentrated Acids:-  
The acid is one which contains the minimum possible amount of water.

Dilution:-
Mixing an acid with water result in decreae in the concentration of ions H2O+ per unit volume. This process is called dilution. 

Scale:
A scale for measuring hydrogen (H+) ion concentration in a solution is known as Scale.