Acids:
Acids are sour in taste.
If hydronium ions are found in a solution, the solution is acidic in nature.
Hydronium ions are the only positively-charged ions (cations) formed when an acid dissolves in water
All the properties of an acid are due to the presence of these ions. The chemical formula of an hydronium
ion is H3O1+.
An acid is known as a 'proton donor'.
Examples of Acids:
Aqua Regia contains concentrated Nitric acid and concentrated Hydrochloric acid in the ratio 1:3.
Aqua Regia means 'Royal Water' in Latin. It is used to dissolve noble metals like gold and platinum.
Milk contains lactic acid. Lactic acid is named after the Latin word 'lac', which means milk.
Vinegar is very dilute acetic acid. The vinegar used in cooking contains approximately 4% of acetic acid.
The chemical formula of acetic acid is CH3COOH.
Sulfuric acid is used in the manufacture of many car batteries. It is also known as 'Oil of Vitriol'.
The chemical formula of Sulfuric acid is H2SO4.
Carbonic acid is responsible for the 'fizz' in soft drinks. The carbonic acid decomposes into Carbon dioxide bubbles.
The chemical formula of Carbonic acid is H2CO3.
Ascorbic acid is the chemical name of Vitamin C. Deficiency of Vitamin C in the body may result in a disease known as scurvy.
The chemical formula of ascorbic acid is C6H8O6.
Properties of acids:
- All acids have a sour taste.
- Acids turn litmus paper blue to red in colour.
- Dilute acids react with certain metals to form hydrogen gas. A salt is also formed.
- Acids react with metallic carbonates and bicarbonates to release carbon dioxide.
- Acids react with alkalis to form salt and water. These reactions are called neutralizations reactions.
- Acids react with metal oxides in the same way as with metal hydroxides (alkalis) producing salt and water.
- Acids are electrolytes and in aqueous solutions they conduct electricity.
Bases:
Bases are bitter in taste and soapy to touch.
If hydroxyl ions are found in a solution, the solution is basic in nature. Hydroxyl ions are the
only negatively-charged ions (anions) formed when a base dissolves in water.
All the properties of a base are due to the presence of these ions.
The chemical formula of an hydroxyl ion is OH1-.
A base is known as a 'proton acceptor'.
Examples of Bases:
Antacids help to neutralize the acidity (of hydrochloric acid) in the stomach.
They chiefly contain two bases, namely Magnesium hydroxide and Aluminum hydroxide.
The chemical formula of Magnesium hydroxide and Aluminum hydroxide is Mg(OH)2 and Al(OH)3 respectively.
Sodium hydroxide is also known as 'Caustic Soda'. Its chemical formula is NaOH.
Potassium hydroxide is also known as 'Caustic Potash'. It is used in the manufacture of alkaline batteries.
Its chemical formula is KOH.
Ammonia is a basic gas which is used in the manufacture of fertilizers such as Urea, Ammonium nitrate, and
Ammonium sulfate. Ammonia is produced for commercial purposes by the Haber's Process.
When dissolved in water, Ammonia forms a base known as Ammonium hydroxide.
The chemical formula of Ammonia is NH3.
Properties of Bases:
- Bases have a bitter taste.
- Bases feel soapy to touch because they dissolve the natural oils in the skin to form soap.
- They change red litmus paper to blue in colour.
- Bases are also electrolytes like acids as they conduct electricity in aqueous solutions.
- Bases react with acids to form salt and water. The reaction is called neutralization reaction as both acids and bases cancel out each other's properties.
- Babes liberate ammonia when warmed with an ammonium salt.
- Bases dissolve certain metals like tin, zinc, aluminum, etc. and nonmetals like silicon but the reaction is slow at room temperature.
- Bases precipitate hydroxides of heavy metals from their salt solution.
Bases react with fats to form soap.
Salts:
A salt is defined as a compound formed by the complete or incomplete replacement of the
hydrogen ion of an acid by a basic radical.
A normal salt is formed by the complete replacement of the hydrogen ion of an acid by
a basic radical whereas an acid salt is formed by the incomplete replacement of the
hydrogen ion of an acid by a basic radical.
Examples of Salts:
Sodium sulfate is a normal salt whereas Sodium bi sulfate is an acid salt.
Sodium sulfide is soluble in water whereas Copper carbonate, Lead chloride, and Barium sulfate are insoluble in water.
Sodium carbonate is used in the manufacture of detergents and glass.
Zinc sulfide is insoluble in water whereas Potassium phosphate, Ammonium carbonate, and Barium chloride are soluble in water.
Ammonium nitrate is used in the manufacture of fertilizers.
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