Acid

Acid are the substances which give hydrogen(H⁺) ion on aqueous solution. Acids are found in nature in different forms. In most of sour fruits acids are found such as

• Citric acid in lemon and orange
• Tartaric acid in pomelo(भोगटे)
• Ascorbic acid in gooseberry(Vitamin C)
  
  
  

Similarly lactic acid in sour milk, fatty acid on fats, acetic acid in vinegar etc. In laboratory mostly hard acids are used both organic and inorganic. For example Nitric Acid(HNO₃), sulfuric acid(H₂SO₄), hydrochloric acid(HCl) etc.

HCl → H⁺ + Cl^-

H₂SO₄ → 2H⁺ + SO₄^2-

CH₃COOH → H⁺ + CH₃COO^-

Acids are classified with two ways

• On the basis of sources acids are classified as organic and inorganic. Acids found on plants and animal body are said to be organic(except HCl found on our stomach). Citric acid, ascorbic acid, tartaric acid acetic acid etc are organic acids. Similarly hydrochloric acid, nitric acid, sulfuric acid etc are inorganic acids.
• On the basis of ionization capacity acids are classified as strong and weak acid. Strong acids liberate more hydrogen ion in aqueous solution than weak acids. Tartaric acid, acetic acid, carbonic acid(H2CO3) etc are weak acid whereas HCL, H2SO4, HNO3 are strong acids.

Properties of acids

• Acids give H+ ion in aqueous solution
• Generally acids have sour taste.
• Acids burn skin
• Metals react with acid and hydrogen is displaced
• Acids reacts with carbonate and bicarbonates to form carbondioxide
• Acids react with bases to form salt and water

Uses of acids

• Sulfuric acid: in lead acid battery, in industries
• Hydrochloric acid: industrial use, to kill germs in our stomach
• Nitric acid: industrial use, metal etching
• Carbonic acid: making soda water
• Acetic acid: making pickles, chatpate(चटपटे)