Acids, Bases & Indicators

Class 10 Chapter 2 Part 1

1. Class 10 Science Chapter 2 Integrated B.Sc. - B.Ed. Name : SANDHYA School Of Education ACIDS, BASES & INDICATORS

2. Observe the following situations carefully:

3. Which of the following would you suggest as a remedy for the following situations– lemon juice/lemon, vinegar or baking soda solution? How do you classify these substance ?

4. Acids are substances that taste sour and are corrosive in nature. These substances are chemically acidic in nature. For example : Orange juice, curd, vinegar, hydrochloric acid , sulphuric acid and nitric acid. Acids

5. Vinegar, a diluted solution of  acetic acid , has various household applications. It is primarily used as a food preservative. Sulfuric acid is widely used in batteries. The batteries used to start the engines of automobiles commonly contain this acid. Examples of Acids

6. Bases are substances that, in aqueous solution, are slippery to the touch and bitter in taste. These substances are chemically basic in nature.  For example - soap, baking soda,ammonium hydroxide, calcium hydroxide. Bases

7. The manufacturing of soap and paper involves the use of sodium hydroxide . As a foaming agent in fire extinguishers – Aluminium hydroxide Examples of Bases

8. Observe these Materials

9. Substances, which are used to test whether a substance is acidic or basic are called indicators. In Plants or plant parts contain useful chemicals that are used for testing an acidic or basic property of a solution are termed as natural indicators. Indicators

10. Let’s test acidic/basic substances using tumeric paper

11. China rose indicator changes to magenta when brought in contact with acids and it changes to green when brought into contact with bases.

12. Litmus is the most commonly used natural indicator which is extracted from lichens. It has a mauve color in distilled water. Litmus : A Natural Indicator

13. Litmus solution is a purple dye, which is extracted from lichen, a plant belonging to the division Thallophyta , and is commonly used as an indicator.When the litmus solution is neither acidic nor basic, its colour is purple. These are called acid-base indicators . Litmus : A Natural Indicator

14. Litmus : A Natural Indicator It turns red when added to an acidic solution & turns blue when added to a basic solution.

15. Red Cabbage : A Natural Indicator The juice of red cabbage is originally purple in colour . Juice of red cabbage turns reddish with acid and turns greenish with base.

16. What is the name of solely sensory nerve and conveys the sense of smell? Olfactory Nerve

17. Substances which change their smell when mixed with acid or base are known as Olfactory Indicators. The olfactory indicators have a characteristics odour . Olfactory Indicators

18. These type of indicators are used in laboratories to check whether a given solution is a basic or an acidic solution by a process known as olfactory titration. This odour in olfactory indicators is changed in acidic or basic solution and helps us in detecting whether a given sample solutions is acidic or basic in nature. Olfactory Indicators

19. Vanilla:Olfactory Indicator

20. The smell of vanilla vanishes with base, but its smell does not vanish with an acid. Vanilla:Olfactory Indicator

21. Synthetic Indicators  Indicators that are synthesized in the laboratory are known as Synthetic Indicators. For example; Phenolphthalein, methyl orange.

22. Synthetic Indicators  Methyl orange is originally orange in colour . It turns into the red with acid and turns into yellow with base.