User:Preeti yadav/Sandbox

ACIDS AND BASES In earlier days acids were defined as the substances which taste sour and base as the bitter substance .But as we know this is not only the criteria to classify substance into acids and bases.So there took a great development in the this field. some natural and synthetic indicators were developed in order to classify substance into acids and bases.Indicators are the substance used to distinguish between different substance. Some of the indicators are:- 1. China Rose 2.Turmeric Powder 3.litmus paper 4.Methyl orange 5.Phenolphthalein 6.Olfactory indicator 7. pH papper All these indicators shows different properties with acids and bases. Later in 1884 Arrhenius defined acids as the substance which can give Hydrogen ions and he even classified acids into strong and weak acids. Strong acids are the acids which ionized completely and weak if they are not completely ionized and can give hydroxide ion.