| The first definition of acids and bases were derived from our taste of them. Acids tasted sour, hence it was derived from the Latin word: ‘acer’, meaning sharp. Bases, to humans, tasted bitter.
In 1776, the Frenchman Antoine Lavoisier discovered that many compounds with oxygen (non-metallic oxides) developed acidic properties in solution. He defined an acid as a non-metal compound containing oxygen.
In 1810, Humphry Davy showed that HCl has acidic properties and contained no oxygen. He redefined an acid as a substance containing hydrogen.
In 1894, Svante Arrhenius redefined the theory to explain that acids contain H+ ions which are liberated in solution. A base, he said, is a substance which contains OH– ions in solution. However this theory does not account for all bases, such as sodium carbonate (Na2CO3).
In 1923, the Danish scientist Johannes Brönsted and Englishman Thomas Lowry proposed independent theories that an acid is a proton donor, a base a proton acceptor.
From Frigid's Chemistry notes
Last edited by Ragerunner; 18 Mar 2004 at 9:59 PM.
|