Chemistry : Acids, Bases & Salts

apid Theory you need to know! eview

The reaction of an acid with a base to produce only salt and water is called a neutralization reaction.

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.

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 OH^1-.

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.

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 bisulfate 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.