Acids, Bases And Salts-Theories
Introduction:
Based on the nature, compounds are classified as acids, bases and salts. The term acid is derived from the latin word ‘acidium’ meaning sour while bases are characterized by their bitter taste and slippery touch. Natural things like tomato, tamarind possess tartaric acid while lemon has citric acid in it.
The earliest idea regarding acids was that all acids necessarily contain oxygen as one of the component but some acids contain only hydrogen and non-metal Ex: HCl, HBr etc while some acids contain oxygen in addition to hydrogen and non-metal called oxyacids. Ex: HNO3 These acids are called mineral acids as they originate from mineral sources. Organic acids have their origin from plant and animal sources. Ex: Formic acid (HCOOH)
Acids and bases are basically distinguished by litmus test. Acids turn blue litmus red and bases turn red litmus blue. Salts are another category of compounds formed from acids and bases. Salts cover all electrovalent compounds having positive and negative radicals formed from corresponding acids and bases. Many different theories are proposed to define acids and bases
Theories of Acids and Bases:
Three different theories are porposed to explain the nature of acids and bases.