Student Study's video: Chemistry Acid Base and Salts Part 01 Class 10 Foundation Jee mains Adv

Chemistry Acid, Base and Salts Part 01 Class 10 Introduction Elements combine to form numerous compounds. On the basis of their chemical properties, compounds can be classified into three categories:  Acids  Bases  Salts Acids and Bases in the Laboratory Indicators An indicator tells us whether a substance is acidic or basic in nature, by the change in colour. Common Indicators  An acid turns blue litmus red and a base turns red litmus blue.  Methyl orange indicator gives a red colour in an acidic solution and gives a yellow colour in a basic solution.  Phenolphthalein is colourless in an acidic solution and gives a pink colour in a basic solution. Olfactory Indicators  Those substances whose odour changes in acidic or basic media are called olfactory indicators. For example: onion, vanilla and clove oil.  On adding sodium hydroxide solution to a cloth strip treated with onion, the smell of the onion is not detected. An acidic solution does not eliminate the smell of the onion. Reaction of Acids & Bases with Metals Acids react with metals to produce salt by displacing hydrogen. For Example: i. When dilute sulphuric acid reacts with the metal zinc, zinc sulphate is formed with the evolution of hydrogen gas. Zn + H2SO4 → ZnSO4 + H2 ii. Zinc is the only metal which reacts with sodium hydroxide to form sodium zincate with the release of hydrogen gas. Zn + 2NaOH → Na2ZnO2 + H2