Uses of Acids and Introduction to Bases

Economic Uses of Acids  

Laboratory Uses:  

- Drying agent: Sulphuric acid (H₂SO₄)  

- Catalyst: Phosphoric acid (H₃PO₄), Sulphuric acid (H₂SO₄)  

- Oxidising agent: Nitric acid (HNO₃)  

Industrial Uses:  

1. Production of explosives  

2. Used as electrolytes in car batteries  

3. Manufacture of other chemicals such as dyes, fertilisers, detergents  

4. Preparation of antiseptics/germicides  

Bases  

A base is any substance that dissolves in water to produce hydroxide ions (OH⁻) as the only negative ion.  

- Bases can also be defined as substances that react with acids (neutralisation) to form salt + water.  

Neutralization Reaction  

Acid + Base → Salt + Water 

This reaction is fundamental in both laboratory and industrial chemistry.  

Types of Bases  

- Metal Oxides: Formed when metals react with oxygen.  

- Metal Hydroxides: Produced when metallic oxides dissolve in water.  

Alkalis  

- Definition: Alkalis are hydroxides that are soluble in water.  

- Not all hydroxides are soluble; those that are insoluble are simply called bases.  

Strength of Alkalis:  

- Strong Alkalis: Ionize completely in water (e.g., NaOH, KOH).  

- Weak Alkalis: Ionize partially in water (e.g., NH₄OH).