This document discusses acids, bases, and indicators. It provides examples of common acids like vinegar and sulfuric acid, and bases like sodium hydroxide and baking soda. Indicators are substances that are used to test whether something is acidic or basic. Natural indicators mentioned include litmus, red cabbage juice, and turmeric paper. Litmus turns red in acid and blue in base. The document also discusses olfactory indicators that change smell in acids and bases, with vanilla given as an example. Finally, it mentions synthetic indicators like phenolphthalein and methyl orange that change color between acid and base.

1. 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

18. • 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

19. • 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

20. Vanilla:Olfactory Indicator

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

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

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