This document discusses acids and bases. It defines them according to Arrhenius' theory as substances that produce H+ ions (acids) or OH- ions (bases) when dissolved in water. Acids have a pH below 7 and taste sour, while bases have a pH above 7 and taste bitter. Examples of common acids and bases are provided, along with their properties. The document also introduces the pH scale and explains how pH values indicate acid strength. Finally, it describes an experiment to test solutions and identify them as acids or bases using blue-colored juice that changes color in their presence.

1. Acid and Base
Chemistry
Mattayomsuksa 4

3. vocabulary

4. arrhenius

5. aqueous

6. solution

7. slippery

8. neutral

9. structure

10. Comparative sentence
We use the comparative to compare
and contrast different objects.

11. One-syllable adjectives : Adj adding – er
: low-lower, cool - cooler, tall – taller, warm –
warmer, etc.
For example
- Lower pH value indicates a stronger acid.
- Higher pH value indicates a stronger base.

12. Acid and Base

13. Arrhenius Acids and Bases
Acids produce H+ in aqueous solutions
water
HCl H+(aq) + Cl- (aq))
Bases produce OH- in aqueous solutions
water
NaOH Na+(aq) + OH- (aq)

14. Acids
Produce H+ (as H3O+) ions in water
Produce a negative ion (-) too
Taste sour
Corrode metals
React with bases to form salts and water
Neutral Substance : Water!

15. Bases
Produce OH- ions in water
Taste bitter, chalky
Are electrolytes
Feel soapy, slippery
React with acids to form salts and water
Neutral Substance : Water!

16. What is the pH scale?
• Acids have a ph from 0-7
• Lower pH value indicates a
stronger acid.
• Bases have a pH from 7-14
• Higher pH value indicates a
stronger base.

17. Some Common Acids
NaOH sodium hydroxide (found in soap)
HCl hydrochloric acid
NaHCo3 sodium bicarbonate acid
HNO3 nitric acid
(found in sanitary ware cleaner)

18. A PH from 0-7 is Acid or Base ?
What produce a negative ions ?
What neutral substance ?

19. Listening quiz game

20. 1 2 3
4 5

21. NaOH , Base

22. HCL , Acid

23. Washing up , Base

24. HNO3 , Acid

25. NaHCo3 , Base

26. Acids and Base
laboratory

27. instruction
You have to do experiment of Acids and
Base then write down transference and
result of lab. After that you have to present
lab result in front of the class.

28. How to do the experiment
- Drop blue- pea juice 5 drops in lemon
juice, orange juice, soap liquid,
and detergent .
- Observe transference of lab.
- Write down the result of lab.

29. LAB result
Solution Transference
Result
( acid or
base)
Lemon juice+
blue- pea juice
Soap liquid+
blue- pea juice
Orange juice+
blue pea juice
Summary of experiment
Detergent+ blue
………………………………………………………………………………………………
pea juice
………………………………………………………………………………………………
………………………………………………………………………………………………