Acids produce H+ ions in water and taste sour, while bases produce OH- ions in water and taste bitter. Acids react with metals to produce hydrogen gas and with bases to form salts and water. The pH scale ranges from 0-14 and is used to measure whether a substance is acidic (below 7) or basic (above 7). Common indicators like litmus paper and the pH scale can be used to identify substances as acidic or basic. Maintaining the proper pH is important for processes like food preservation, plant growth, and human bodily functions.

2. ACID OR BASE?

3. ACIDS
Produce H+ (as H3O+) ions in water (the hydronium
ion is a hydrogen ion attached to a water molecule)
Taste sour
React with certain metals to produce hydrogen gas--
Corrode metals
Electrolytes- conduct electricity
React with bases to form a salt and water

4. ACIDS

5. BASES
Produce OH- ions in water
Taste bitter, chalky
Are electrolytes
Feel soapy, slippery
React with acids to form salts and water

6. BASES

7. QUESTIONS:
How do we know that a thing is
ACIDIC or BASIC in nature?
Do we have to taste everything
to find out it’s nature?

8. METHOD TO IDENTIFY
ACIDIC AND BASIC MIXTURE

9. 1. INDICATOR
-is a dye that changes into a different
color depending on whether it is in acid or
in base.
Ex. Litmus, Plants materials

10. 1. INDICATOR

11. 2. PH SCALE
• extends from 0 to 14
• discovered by Danish
Biochemist S.P.L. SORENSEN

12. THE PH VALUES OF SOME
SAMPLES OF MATTER

13. THE PH VALUES OF SOME
SAMPLES OF MATTER
Sample pH
Gastric juice 1.6-1.8
Lemon juice 2.1
Vinegar 2.5
Soft drinks 2.0-4.0
Urine 5.5-7.0
Rainwater(unpolluted) 5.6
Milk 6.3-6.6
Saliva 6.2-7.4
Pure Water 7
Blood 7.4
Fresh egg white 7.6-8.0
seawater 8.4
Detergent 11
bleach 12.8
Drain cleaner 13.0

14. IMPORTANCE OF PH

15. 1. PH AND THE
HUMAN BODY
perform specific
functions to balance the
pH levels in the body

16. 2.USE OF PH FOOD PROCESSING
AND FRUIT PRESERVATION
 changes in pH affect
the growth of
microorganism, which
cause food spoilage

17. 3.CONTROL OF PH IN SOIL
 some plants grow well
in acidic soil while
others prefer basic
soil.

18. 4.PH OF RAINWATER
the acidic pollutants in the air
that come from the burning of
fuels used in power plants,
factories and vehicles produce
gases which are acidic.

19. 4.PH OF RAINWATER
the acidic pollutants in the air
that come from the burning of
fuels used in power plants,
factories and vehicles produce
gases which are acidic.

20. 5. MAINTAINING PH OF
PERSONAL CARE PRODUCTS
-to avoid harmful effects on
the body.