Introduction

Substances with a sour taste are regarded as acids. Lemon juice, vinegar, grapefruit juice and spoilt milk, etc. taste sour since they are acidic. Many substances can be identified as acids based on their taste but some of the acids like Sulphuric acid have very strong action on the skin which means that they are corrosive in nature. In such cases, it would be according to the modern definition

An acid may be defined as a substance which releases one or more H+ ions in aqueous solution.